Washington Administrative Code › Title 296 - Labor and Industries, Department of › Chapter 296-307 - Safety standards for agriculture › INDOOR OPERATIONS › Part T - Electrical › Section 296-307-38018 - Use and maintenance of electrical protective devices

Current through Register Vol. 24-14, July 15, 2024
(1) Electrical protective equipment must be
				  maintained in a safe, reliable condition.
(2) The following specific requirements apply
				  to insulating blankets, covers, line hose, gloves, and sleeves made of rubber:
(a) Maximum use voltages must meet the
				  requirements in Table 4.
(b)
				  Insulating equipment must be inspected for damage before each day's use and
				  immediately following any incident that can reasonably be suspected of having
				  caused damage. Insulating gloves must be given an air test, along with the
				  inspection.
(c) Insulating
				  equipment with any of the following defects must not be used:
(i) A hole, tear, puncture, or cut;
(ii) Ozone cutting or ozone checking (the
				  cutting action produced by ozone on rubber under mechanical stress into a
				  series of interlacing cracks);
(iii) An embedded foreign object;
(iv) Any of the following texture changes:
				  Swelling, softening, hardening, or becoming sticky or inelastic;
(v) Any other defect that damages the
				  insulating properties.
(d) Insulating equipment found to have other
				  defects that might affect its insulating properties must be removed from
				  service and returned for testing under (h) of this subsection.
(e) Insulating equipment must be cleaned as
				  needed to remove foreign substances.
(f) Insulating equipment must be stored in
				  such a location and in such a manner as to protect it from light, temperature
				  extremes, excessive humidity, ozone, and other injurious substances and
				  conditions.
(g) Protector gloves
				  must be worn over insulating gloves.
(h) Electrical protective equipment must be
				  subjected to periodic electrical tests. Test voltages and the maximum intervals
				  between tests must be according to Table 4 and Table 5.
(i) The test method used must reliably
				  indicate whether the insulating equipment can withstand the voltages involved.
Note:
Standard electrical test methods considered as
								meeting this requirement are given in the following national consensus
								standards:
1. American Society for Testing and Materials
								(ASTM) D 120-87, Specification for Rubber Insulating Gloves.
2. ASTM D 1048-93, Specification for Rubber
								Insulating Blankets.
3. ASTM D 1049-93, Specification for Rubber
								Insulating Covers.
4. ASTM D 1050-90, Specification for Rubber
								Insulating Line Hose.
5. ASTM D 1051-87, Specification for Rubber
								Insulating Sleeves.
6. ASTM F 478-92, Specification for In-Service
								Care of Insulating Line Hose and Covers.
7. ASTM F 479-88a, Specification for In-Service
								Care of Insulating Blankets.
8. ASTM F 496-93b, Specification for In-Service
								Care of Insulating Gloves and Sleeves.
(j) Insulating equipment that fails
				  inspections or electrical tests must not be used by employees, except as
				  follows:
(i) Rubber insulating line hose could
				  be used in shorter lengths with the defective portion cut off.
(ii) Rubber insulating blankets could be
				  repaired using a compatible patch that results in physical and electrical
				  properties equal to those of the blanket.
(iii) Rubber insulating blankets could be
				  salvaged by severing the defective area from the undamaged portion of the
				  blanket. The resulting undamaged area must not be smaller than twenty-two
				  inches by twenty-two inches (560 mm by 560 mm) for Class 1, 2, 3, and 4
				  blankets.
(k) Repaired
				  insulating equipment must be retested before it may be used by
				  employees.
(l) The employer must
				  certify that equipment has been tested in accordance with the requirements of
				  (h), (i), and (k) of this subsection. The certification must identify the
				  equipment that passed the test and the date it was tested.
Note:
This requirement may be met by marking the
								equipment and entering the results of the tests and the dates of testing onto
								logs.
Table 1
A-C Proof-Test Requirements Maximum
								proof-test current, mA (gloves only)
Class of equipment
Proof-test voltage rms V
267 mm (10.5 in.) glove
356 mm (14 in.) glove
406 mm (16 in.) glove
457 mm (18 in.) glove
0
5,000
8
12
14
16
1
10,000
14
16
18
2
20,000
16
18
20
3
30,000
18
20
22
4
40,000
22
24
Table 2
D-C Proof-Test
								Requirements
Class of Equipment
Proof-test voltage
0
20,000
1
40,000
2
50,000
3
60,000
4
70,000
Note
: The d-c voltages listed in
								this table are not appropriate for proof testing rubber insulating line hose or
								covers. For this equipment, d-c proof-tests must use a voltage high enough to
								indicate that the equipment can be safely used at the voltages listed in Table
								3. See ASTM D 1050-90 and ASTM D 1049-88 for further information on proof tests
								for rubber insulating line hose and covers.
Table 3
Glove Tests-Water
								Level1,
																	2
A-C proof-test
D-C proof-test
Class of glove
mm.
in.
mm.
in.
0
38
1. 5
38
1. 5
1
38
1. 5
51
2.0
2
64
2.5
76
3.0
3
89
3.5
102
4.0
4
127
5.0
153
6.0
1The water level is given as
								the clearance from the cuff of the glove to the water line, with a tolerance of
								13 mm. (0.5 in.)
.2If atmospheric
								conditions make the specified clearances impractical, the clearances may be
								increased by a maximum of 25 mm. (1 in.)
Table 4
Rubber Insulating Equipment
Voltage Requirements
Class of equipment
Maximum usevoltage1
								a-c-rms
Retest voltage2a-c-rms
Retest voltage2d-c-rms
0
1,000
5,000
20,000
1
7,500
10,000
40,000
2
17,000
20,000
50,000
Class of equipment
Maximum usevoltage1
								a-c-rms
Retest voltage2a-c-rms
Retest voltage2d-c-rms
3
26,500
30,000
60,000
4
36,000
40,000
70,000
Note
: Rubber gloves must only be
								used on voltages of 5000 volts phase to phase or less.
1The maximum use voltage
								is the a-c voltage (rms) classification of the protective equipment that
								designates the maximum nominal design/voltage of the energized system that may
								be safely worked. The nominal voltage design is equal to the phase-to-phase
								voltage on multiphase circuits. However, the phase-to-ground potential is
								considered to be the nominal design/voltage:
(a)If there is no multiphase exposure in a system
								area and if the voltage exposure is limited to the phase-to-ground potential,
								or
(b)If the electrical equipment and devices are
								insulated or isolated or both so that the multiphase exposure on a grounded wye
								circuit is removed.
2The proof-test voltage
								must be applied continuously for at least one minute, but no more than three
								minutes.
Table 5 Rubber Insulating Equipment Test
								Intervals
Type of equipment
When to test
Rubber insulating line hose
Upon indication that insulating value is
								suspect
Rubber insulating covers
Upon indication that insulating value is
								suspect
Rubber insulating blankets
Before first issue and every 12 months
								thereafter
Rubber insulating gloves
Before first issue and every 6 months
								thereafter
Rubber insulating sleeves
Before first issue and every 12 months
								thereafter