Abstract:
A non-venting current limiting fuse for mounting in a cutout comprises a high current fuse component and a low current fuse component housed in separate compartments of a housing and connected in series. Interruption of a low current overload results in operation of the low current fuse component only, with the high current component being unaffected. The low current fuse component is removable from the housing such that when a low current overload situation exists, the low current fuse component can be simply removed and replaced without the need for replacement of the more costly high current fuse component.

Description:
FIELD OF THE INVENTION 
     The present invention relates to non-venting cutout-mounted current limiting fuses for use in protecting power distribution equipment such as overhead distribution transformers and capacitors. 
     BACKGROUND OF THE INVENTION 
     Several traditional methods exist to provide overcurrent protection for distribution equipment. Some of these methods include a distribution fuse cutout with an expulsion fuse link, a distribution cutout in combination with a back-up current limiting fuse (CLF), internal expulsion and current limiting fuses such as completely self protected transformers, and single general-purpose CLF&#39;s in a cutout. Each of these methods have their inherent advantages and disadvantages. 
     The expulsion fuse in a fuse cutout is inexpensive, but provides no energy limiting ability. There has been concern at many utilities about the hot particles and gases that are ejected when expulsion fuses operate. This is particularly dangerous when a lineman is on the pole and closes a cutout into a fault. 
     The use of two fuses in series allows the replacement of only the unit that has interrupted the overcurrent, thus saving the cost of replacing the intact fuse. The expulsion fuse in this combination is sized to blow on low currents. Only when the available fault current is high, does the more expensive back-up current-limiting fuse operate. The distribution cutout also provides a convenient means of disconnection for the transformer. The disadvantage of this two-fuse method is in the installation space required, and the necessity to stock and carry both of these types of fuses. Also, the venting problem is not entirely eliminated and there is no indication of the operation of the back-up CLF. Also, back-up CLF&#39;s are prone to eventful failure if they become damaged and operated on a current below their minimum interrupting rating. 
     Completely self-protected (CSP) transformers offer a version of the two-fuse method, with the CLF located inside the transformer tank. The internal CLF provides a more compact installation, but the CLF cannot be easily accessed. Some utilities using CSP overhead transformers, however, are unhappy with some aspects of these units. In particular, they would like to have the internal fuses, which are currently mounted inside the transformer tank, accessible for replacement. Also, some utilities find the internal molded case breakers are prone to nuisance blowing and do not allow the utility to emergency load their transformers. At the same time these utilities appreciate the compactness and ease of installation of the CSP units. CSP transformers are particularly desirable in voltage conversion applications when use of the original poles does not allow space for a cutout and back-up CLF to be mounted. 
     Where space is limited and the presence of an expulsion fuse is undesirable, a single cutout-mounted general-purpose fuse is sometimes preferred. The general-purpose CLF is more compact, but the entire expensive unit must be replaced whenever the fuse operates, even though it may have only been required to interrupt a low current that could have been interrupted by an inexpensive fuse link. 
     To date there has not been a single solution which address the needs for a compact, inexpensive cutout-mounted fuse which is non-venting and replaceable. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the above-discussed problems of the prior art by providing a non-venting cutout-mounted current limiting fuse having a high current fuse element and a low current fuse element connected in series and housed in separate compartments of a compact housing. Interruption of a low current overload results in operation of the low current fuse element only, with the high current element being unaffected. The low current fuse element is contained in a low current fuse component which is removable from the housing such that when a low current overload situation exists, the low current fuse component can be simply removed and replaced without the need for replacement of the more costly high current fuse element. 
     Furthermore, the low current fuse component is constructed in such a way that the problem of gas and particle emissions resulting from operation of the low current element is either reduced or eliminated. Specifically, the low current fuse element is contained within a separate housing and is separated from the walls thereof by an energy absorbing material such as sand. 
     Accordingly, in one aspect the present invention provides a current limiting fuse for mounting in a cutout, comprising: a first housing having first and second compartments; a first fuse element adapted to operate at a high current, the first fuse element contained within the first compartment; and a second fuse element adapted to operate at low current, the second fuse element contained within the second compartment, wherein the first and second fuse elements are electrically connected in series. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further features and advantages of the method and device embodying the present invention will now be described and made clearer from the ensuing description, reference being had to the accompanying drawings, in which: 
     FIG. 1 is a side view of a non-venting cutout fuse according to a preferred embodiment of the present invention mounted in a conventional distribution cutout; 
     FIG. 2 is an isolated cross-sectional side view of the non-venting cutout mounted fuse shown in FIG. 1; 
     FIG. 3 is a cross-sectional side view of the fuse of FIG. 1 showing the low current fuse component removed; 
     FIGS. 4 to  16  are current and voltage waveforms for non-venting cutout mounted fuses according to the present invention; and 
     FIG. 17 is a current/time curve for the non-venting cutout mounted fuse according to the present invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     As a solution to the shortcomings of existing current limiting apparatus for overhead distribution equipment, the present invention, a non-venting cutout-mounted fuse (NVCF), has been developed. The NVCF is a single fuse unit of the same dimensions as the present general-purpose CLF, however, the NVCF allows inexpensive resetting of the fuse after low current operations. 
     In FIG. 1, a preferred NVCF according to the invention mounted in a conventional distribution cutout is shown generally as item  10 . The cutout and the NVCF are shown as items  12  and  14 , respectively. A disconnecting handle  16  is shown as comprising part of the hardware required to mount the NVCF into the distribution cutout. Referring now to FIG. 2, fuse  14  is housed in a fiber-glass tube  18  similar to that used to house traditional full-range current limiting fuses. In contrast to the conventional CLF, however, external fiber-glass tube  18  houses two components: a replaceable low-current fuse component  20 , and a high-current fuse component  22 . In one preferred embodiment of a non-venting cutout fuse according to the invention, the fiber-glass tube  18  comprises a cylinder having a length of about 360 mm, an outside diameter of about 56 mm and an inside diameter of about 51 mm. 
     Tube  18  is divided into two separate compartments, a first compartment  24  configured to contain high current fuse component  22 , and a second compartment  26 , which is configured to contain replaceable low current fuse component  20 . In preferred fuse  14  in which tube  18  has the above dimensions, the first compartment  24  preferably has a length of about 264 mm and the second compartment  26  preferably has a length of about 85 to 90 mm. Compartments  24  and  26  are separated by barrier  28  which is preferably comprised of a fiber-glass disc having a thickness of about 5 mm and being of a diameter to fit snugly inside tube  18 . 
     The tube  18  is closed at its respective ends  30  and  32  by end caps  34  and  36 , each of which comprise a flat end wall and a cylindrical side wall. Specifically, end cap  34  seals end  30  of second compartment  26  and comprises end wall  38  and side wall  40 , while end cap  36  seals the end of the first compartment  24  and comprises end wall  42  and side wall  44 . Where tube  18  has the above dimensions, the cylindrical side walls  40 ,  44  preferably each have a length of about 32 mm and a diameter of about 58 mm, to thereby allow caps  34  and  36  to fit over the ends of tube  18 . The end caps  34  and  36  are preferably comprised of an electrically conductive material, with copper being preferred. End cap  36  is preferably sealed to end  32  of tube  18  by a hardened resin material, such as an epoxy resin. The inner surface of end wall  38  of cap  34  is preferably provided with a resilient sealing material such as a rubber seal  46  to seal the end of second compartment  26 . The rubber seal  46  may preferably have a thickness of about 2 mm. 
     Referring now to FIGS. 2 and 3, the housing of high current fuse component  22  is formed by first compartment  24  of tube  18  closed at its opposite ends by end cap  36  and barrier  28 . Inside the housing is provided a high current fuse element  48  comprising a metal ribbon supported on an internal support  50 , both of which are separated from the inside wall of tube  18  by an energy absorbing filler  52 , preferably sand. High current fuse element  48  is made of an electrically conductive material which melts at relatively low temperature, preferably silver, while support  50  is made of a non-conducting material such as mica. In fuse  14  having the above dimensions, the high current fuse element  48  is preferably comprised of a silver ribbon having spaced holes  53 , and has a length of about 92 cm, a width of about 4.75 mm and a thickness of about 0.13 mm. The internal mica support  50  is preferably formed with square notches  54  in a manner known in the art. High current fuse element  48  is wound around notched support  50  at regularly spaced intervals of about 24 mm between the centers of adjacent coils, and is in electrical contact with the end cap  36 , for example by being soldered thereto as at point  56 . 
     The high current fuse component  22  of the present invention serves to interrupt high magnitude faults. This is accomplished by melting of high current fuse element  48 . Upon melting at all of the notched locations of fuse element  48 , high current fuse component  22  develops an arcing voltage that opposes and overcomes the system voltage and forces the current to zero. The first compartment  24  containing the high current fuse component  22  can also incorporate an indicator button (not shown) to indicate the status of high current fuse component  22 . 
     The non-conductive barrier  28  separating compartments  24  and  26  is provided with a centrally located aperture  58  through which a conductive connector  60  passes. A first end  62  of connector  60  is in electrical contact with high current fuse element  48 , while a second, threaded end  64  of connector  60  projects into second compartment  26 . Connector  60  is secured to barrier  28  by a nut  66  threaded onto the second end  64  of connector  60 , and the aperture  58  and edges of barrier  28  are sealed by a layer of hardened resin  68 , such as an epoxy resin. 
     As shown in FIG. 3, low current fuse component  20  is contained in a small cylindrical housing  70  which is preferably made from fiber-glass. Housing  70  comprises a tube  72  sealed at its ends by end walls  74  and  76 . Tube  72  has a length and diameter which allow it to fit inside second compartment  26  of fuse  14 . The inner surfaces of the respective end walls  74 ,  76  are preferably provided with recessed edges  78 ,  80  such that the end walls  74 ,  76  project slightly into the ends of tube  72  and completely cover the ends thereof. Where fuse  14  has the above dimensions, tube  72  preferably has an outside diameter of about 48 mm, an inside diameter of about 44 mm and a length of about 77 mm. End walls  74  and  76  preferably have a diameter of 48 mm, a thickness of about 10 mm, with the edges  78  and  80  being recessed by about 5 mm. 
     Low current fuse component  20  comprises an electrically conductive low current fuse element  82  wound around a support  84 , both of which are separated from the inner surfaces of housing  70  by energy absorbing filler  86 , preferably sand. Low current fuse element  82  preferably comprises a thin conductive wire and is enclosed in an insulating casing  90  such as silicon rubber. Support  84  is preferably comprised of mica and has square notches  92 , similar to mica support  50  described above. Where housing  70  has the above-described dimensions, the low current fuse element  82  preferably comprises a tin wire of diameter 1.25 mm and length 170 mm. 
     End wall  76  of housing  70  is provided with a centrally located aperture  94  through which projects an electrically conductive connector  96 . Connector  96  has an enlarged head  98  which is located inside housing  70  and is in engagement with the inner surface of end wall  76 . A shank  100  projects from the head  98  of connector  96 , extends completely through end wall  76 , and protrudes slightly therefrom. Connector  96  is provided with a threaded bore  102  extending through the center of the shank  100  and into the head  98 . Threaded bore  102  is adapted to receive the second end  64  of connector  60  projecting into second compartment  26  of tube  18 . 
     Embedded in the opposite end wall  74  of housing  70  is the head  104  of an electrically conductive connector  106 . A threaded shank  108  of connector  106  projects outwardly from the end wall  74  and is adapted to be threaded into a nut  110  which is rigidly secured to the outer surface of the end wall  38  of end cap  34 . The low current fuse element  82  is in electrical contact with connectors  96  and  106 , thereby permitting electrical current to flow through low current fuse component  20  from one end of housing  70  to the other. 
     The fuse  14  is assembled by inserting low current fuse component  20  into second compartment  26  and threading the second end  64  of connector  60  into the bore  102  of connector  96 , until a firm connection is achieved. End cap  34  is then secured over the end  30  of tube  18  by threading connector  106  into nut  110  until seal  46  tightly engages the end  30  of tube  18 , thereby ensuring that fuse component  20  is sealed within compartment  26 . When the fuse  14  is fully assembled, a continuous electrically conductive path is provided from end cap  34  to cap  36  via high current fuse element  48  and low current fuse element  82 . 
     A conventional charge operated blown fuse indicator can also be housed within housing  70  inside end wall  74  to visually indicate when the low current fuse component  20  has been operated. The indicator comprises a small gunpowder charge which, when activated, fires a pin through the end wall  74  of housing  70 . Where an indicator is used, a portion of the end wall  74  of housing  70  and the end wall  38  of end cap  34  may preferably be of reduced thickness to permit penetration by the pin. In another preferred embodiment, the indicator device doubles as a striker pin to activate the drop-out feature of the cutout. 
     The purpose of low-current component  20  of the non-venting cutout fuse  14  according to the invention is to interrupt low current overloads. It does so by the melting of the low current fuse element  82 . When fuse element  82  melts, arcing and gases are generated and pieces of molten tin are blown out of tight fitting silicon tube  90 . However, since low current fuse component  20  is filled with sand, the fuse component  20  and fuse  14  are able to withstand rupture and thereby withstand line potential. Furthermore, since compartments  24  and  26  are separated by barrier  28 , and low current fuse component  20  is sealed within housing  70 , operation of low current fuse component  20  does not damage high current fuse component  22 , allowing high current fuse component  22  to be re-used. 
     After the fuse  14  operates to interrupt a current, it is removed and checked to determine which fuse component has operated. If only low current fuse component  20  is blown, then this component can be replaced and the fuse re-installed. If high current fuse component  22  has also blown, the entire fuse  14  must be replaced. 
     EXAMPLES 
     To further illustrate the function and the effectiveness of the invention, a series of tests were conducted with the fuse  14  having the construction and dimensions described above. The tests were designed to demonstrate how the replaceable low current fuse component could withstand, without failure, the large amounts of energy that it is forced to dissipate. The tests were also performed to verify the predicted time-current characteristics of the invention. 
     The invention was tested basically with two different circuits at the Ontario Hydro&#39;s High current laboratory. The circuits were chosen as the ones that were expected to be representative of two of the most onerous fault current conditions that the fuse would experience in the field. Both circuits had a nominal 15.5 kV open circuit voltage. It should be noted that the test program does by no means, and is not intended to, represent a full series of standards tests according to ANSI C37.41 “Design Tests for High Voltage Fuses”. This standard, particularly the parts pertaining to interruption tests, was however, used as a guideline for the testing procedures. 
     The first test circuit provided currents from 20 to 100 Arms with relatively low X/R values. This provided currents just above the long time minimum melting characteristic of the fuse and required the low current element of the fuse to interrupt after a long period of heating. The ability of the small low current element housing to withstand such heating was of interest. The second test circuit provided a high fault current and was used to verify that the high current fuse component module would indeed interrupt on high currents. 
     For testing, the low current fuse component was connected to the high current fuse component and enclosed in the tube as described above, and mounted in a cutout as illustrated in FIG.  1 . The resistance of each component was measured before and after each test to verify which component had operated and whether the intact components had suffered any damage during the testing. After the fuse operation, the voltage was maintained on the open fuse for a period of 1 or 10 minutes to ascertain whether or not the open fuse could withstand the system voltage without reigniting. 
     Test Results 
     The specific test conditions and results are summarized in Table 1. The actual current and voltage waveforms from the tests are provided in FIGS. 4 to  16 . In Table 1, the low-current elements are referred to as NVF-1, NVF-2 etc, and the high current module is referred to as NVF-2B. Tests 1 to 6 were performed at low currents (20 to 100 A). The results show that the low current fuse component of the present invention operated successfully during each test to interrupt the current and withstand the voltage after the fuse had operated. In these tests the high current use element was left intact and undamaged. 
     Test 7 is a high current (5.5 kA) interruption test in which the high current fuse component of the invention successfully interrupted the fault current and withstood the recovery and 1 minute withstand voltage. 
     The current/time curve in FIG. 17 shows the calculated current/time curve and the current and time coordinates at which the NVCF prototypes successfully interrupted. (Test 1 is not plotted since it was conducted on a slightly different initial prototype. The maximum interrupting current test at 5.5 kA and 0.75 ms is off the scale of this graph.) As shown in FIG. 17, there is a distinct break in the current/time curve at about 140 A. This is the point at which the high-current element takes over interruption from the low-current element. It is also to be noted that the calculated curve was an “average” melting curve. The measured current/time points on occasion fall below this calculated curve since there is an expected plus and minus tolerance to the calculated curve. 
     The test result prove the technical feasibility of the invention. Both the high and low current fuse components of the fuse successfully interrupted at the appropriate fault current levels. FIG. 16 also verifies that the calculations used in the design of the low current element were valid as a prediction of the average melting characteristic of that element. 
     The fuse is preferably designed to be installed as a direct replacement for distribution expulsion fuse links. The hardware required to mount the fuse in the cutout would be a one-time purchase. Once installed, the new fuse offers non-venting and current limiting overcurrent protection. When the fuse operates the cutout will drop out. The fuse should then be inspected to determine if the high or low current element has operated by looking at the fuse indicators. If the low current element has operated it is simply replaced and the whole fuse closed into the cutout. If the high current element has operated, there has been a major fault in the protected equipment. The equipment should be inspected, likely replaced and the entire fuse unit replaced and reclosed at the appropriate time. 
     As evident from the above, the present invention has several significant advantages over conventional fusing. It eliminates the hazard associated with the violent ejection of particles from expulsion fuses. It offers all of the advantages of the two-fuse system in a convenient single fuse unit. It is as compact as the present general-purpose CLF, however, the present invention is less expensive since it allows resetting of a low cost module after low current operations. 
     In contrast to distribution fuse links, the present invention does not allow any ejection of hot particles or gas when it operates and does not generate loud noise upon operation. This allows line staff to operate a cutout with confidence that they will not be subjected to expulsion by-products and explosive noises if the fuse is closed onto a fault. 
     The present invention offers all the advantages of the two fuse system with the expulsion and current limiting fuse as well as overcoming the disadvantages of this system. The present invention allows replacement of only the unit that has interrupted the overcurrent, thus saving the cost of replacing the intact fuse. The expulsion component is sized to blow on low currents. Only when the available fault current is high, does the more expensive current-limiting fuse operate. The present invention also allows the cutout to continue to act as a means of disconnecting the transformer. Beyond the capabilities of the two-fuse system, the present invention requires no more installation space than the cutout itself The present invention also eliminates the venting whereas at best it is only reduced by the two-fuse system. 
     It will be appreciated that the principles of the present invention may be applied to the production of non-venting cutout mounted fuses having a variety of ampere ratings by varying the characteristics of the high and low current fuse elements and/or other components of the fuse. It will also be appreciated that the preferred non-venting cutout mounted fuse described above has a relatively low ampere rating (roughly about 10 A), having a low current fuse element which operates at about 20 A to 100 A and a high current element which operates from above about 100 A up to about 50,000 A. 
     The invention having been so described, certain modifications and adaptions will be obvious to those skilled in the art. In particular, it is to be appreciated that the construction and dimensions of the preferred fuse described above can be varied without departing from the spirit and scope of the invention. The invention includes all such modifications and adaptions which follow in the scope of the appended claims. 
     
       
         
               
             
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                  NON-VENTING FUSE TEST RESULTS 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                   
                 Resist 
                 Resist 
                   
                   
                   
                   
                   
               
               
                   
                   
                 Low 
                 High 
                 Prospect 
                 Test 
                   
                   
                 Time 
               
             
          
           
               
                 Test 
                   
                 Element 
                 Element 
                 Current 
                 Volt 
                   
                 Close 
                 Melt 
                 Arc 
                 Total 
               
               
                 No. 
                 Fuse ID 
                 (mohm) 
                 (mohm) 
                 (A rms) 
                 (kV) 
                 X/R 
                 Angle 
                 (ms) 
                 (ms) 
                 (ms) 
               
               
                   
               
             
          
           
               
                 1 
                 NVF-1 
                 B: 4.8 
                 B: 29.7 
                 105 
                 15.1 
                 &lt;1 
                 Rand 
                 ND 
                 ND 
                 1.8 s 
               
               
                   
                   
                 A: Open 
                 A: 28.2 
                   
                   
                   
                   
                   
                   
                 + 
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 31 s 
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 cool 
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 + 
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 7.6 s 
               
               
                 2 
                 NVF-2 
                 B: 25.8 
                 B: 47.4 
                   
                 16.8 
                 2.21 
                 Rand 
                 155.7 
                 18.7 
                 174.4 
               
               
                   
                 &amp; 
                 A: Open 
                 A: 46.7 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 NVF-2B 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 3 
                 NVF-4 
                 B: 15.1 
                 B: 46.7 
                 83.8 
                 15.9 
                 2.21 
                 Rand 
                 684.5 
                 14.5 
                 899 
               
               
                   
                 &amp; 
                 A: Open 
                 A: 46.7 
               
               
                   
                 NVF-2B 
               
               
                 4 
                 NVF-5 
                 B: 17.8 
                 B: 46.7 
                 23.4 
                 15.9 
                 3.16 
                 Rand 
                 40.3 s 
                 21 ms 
                 40.3 s 
               
               
                   
                 &amp; 
                 A: Open 
                 A: 47.7 
               
               
                   
                 NVF-2B 
               
               
                 5 
                 NVF-3 
                 B: 7.3 
                 B: 47.7 
                 23.2 
                 15.9 
                 3.15 
                 Rand 
                 NA 
                 NA 
                 15 
               
               
                   
                 &amp; 
                 A: 7.3 
                 A: 53.5 
                 24 
                 15.9 
                 3.2 
                 Rand 
                   
                   
                 min 
               
               
                   
                 NVF-2B 
                   
                 Hot 
                 35.2 
                 15.9 
                 2 
                 Rand 
                   
                   
                 15 
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 min 
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 3 min 
               
               
                 6 
                 NVF-6 
                 B: 16.7 
                 B: 53.5 
                 23.2 
                 15.9 
                 3.2 
                 Rand 
                 115 s 
                 19 + 
                 115 s 
               
               
                   
                 &amp; 
                 A: Open 
                 A: 46.9 
                   
                   
                   
                   
                   
                 16 clr 
               
               
                   
                 NVF-2B 
                   
                   
                   
                   
                   
                   
                   
                 + 6.6 
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 = 44 
               
               
                 7 
                 NVF-3 
                 B: 7.2 
                 B: 47.3 
                 5.6 kA 
                 15.6 
                 8.3 
                 1 init 54° 
                 0.75 
                 4.5 
                 6.25 
               
               
                   
                 &amp; 
                 A: 7.3 
                 A: Open 
                   
                   
                   
                 after V n   
               
               
                   
                 NVF-2B 
                   
                   
                   
                   
                   
                 arc init 
               
               
                   
                   
                   
                   
                   
                   
                   
                 71° 
               
               
                   
                   
                   
                   
                   
                   
                   
                 after V n   
               
               
                   
               
             
          
           
               
                   
                   
                   
                   
                   
                   
                 Rec 
               
               
                   
                   
                 I 2 t 
                 Energy 
                   
                   
                 Volt 
               
             
          
           
               
                   
                 Test 
                 Melt 
                 Arc 
                 Total 
                 Melt 
                 Arc 
                 Total 
                 I Pk   
                 V Pk   
                 Dur 
               
               
                   
                 No. 
                 (kA 2 s) 
                 (As) 
                 (kA 2 s) 
                 (J) 
                 (kJ) 
                 (kJ) 
                 (kA) 
                 (kV) 
                 (min) 
               
               
                   
                   
               
               
                   
                 1 
                 ND 
                 ND 
                 ND 
                 ND 
                 ND 
                 ND 
                 ND 
                 ND 
                 10 min 
               
               
                   
                 2 
                 1.38 
                 160 
                 1.54 
                 118 
                 0.7 
                 0.71 
                 .13 
                 22 
                 10 s + 
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 30 s ols 
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 + 1 min 
               
               
                   
                 3 
                 8.08 
                 134 
                 6.2  
                 NA 
                 1.0 
                 NA 
                 .13 
                 22 
                 1 min 
               
               
                   
                 4 
                 NA 
                 11.3 
                 NA 
                 NA 
                 0.35 
                 NA 
                 .03 
                 22 
                 10 min 
               
               
                   
                 5 
                 NA 
                 NA 
                 NA 
                 NA 
                 NA 
                 NA 
                 NA 
                 NA 
                 no melt 
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 no melt 
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 no melt 
               
               
                   
                 6 
                 NA 
                 14.6 
                 NA 
                 NA 
                 0.31 
                 NA 
                 .03 
                 23 
                 10 min 
               
               
                   
                 7 
                 1.62 
                 7.5 
                 9.13 
                 147 
                 108 
                 108 
                 2.8 
                 36.7 
                 1 min