Electrical service disconnect boxes for conveying power to adjacent electrical appliances such as air conditioners

This invention provides a device which facilitates electrical wiring and equipment costs for electricians installing disconnect boxes, typically in the vicinity of an outside air conditioner unit. Thus, an improved disconnect box for protection of an electrician who is servicing an electrical appliance such as an outside air conditioner is provided which incorporates an integrally mounted auxiliary electric socket accessory giving the electrician a source of power for use while the electrician is safely assured that there is no power connected to the electrical appliance being serviced. The auxiliary electrical socket accessory may optionally be connected to a power line source as a full time electric plug outlet or one only accessible when the disconnect box is conditioned to disconnect power from the electrical appliance. Provisions are made for protection of the electrical socket accessory with fusing or circuit breaker protection and ground fault protected electrical input wiring to the electrical socket. The disconnect box is preferably weatherproofed for outside use to serve as a common housing for waterproofing the electrical socket. By provision of the improved disconnect box, the electrician can more efficiently install an auxiliary access socket for use of the electrician when the electrical appliance is disconnected either in retrofit or initial installations.

TECHNICAL FIELD 
This invention relates to electrical wiring accessories, and more 
particularly it relates to electrical service disconnect boxes having 
disconnect switches, such plug blocks manually pulled by an attending 
electrician, for interrupting power conveyed to electrical appliances, 
such as air conditioners, when being serviced. 
BACKGROUND ART 
The installation of auxiliary electrical plugs in a location facilitating 
use of an electrician during servicing an electrical appliance, typically 
an outside air conditioner unit, either in an initial installation or a 
retrofit installation, takes considerable electrician time and equipment 
cost. Thus, it is required to conveniently locate the auxiliary electrical 
plug accessory, to install a weatherproof housing upon a masonry wall, or 
the like, and to make interacting electrical connections such as 
installation of new ground fault protected wiring lines to the plug 
accessory. 
There is not any off-the-shelf electrical accessory currently available to 
aid the electrician in this special task. 
Accordingly it is an objective of this invention to resolve the prior art 
problem and to reduce the electrician's time and equipment costs in a 
manner that the electrician is conveniently provided with an electrical 
plug accessory that is safe, simpler to install and consistent with 
applicable electrical wiring code requirements. 
DISCLOSURE OF THE INVENTION 
This invention incorporates a service plug accessory for the electrician's 
use while servicing a disconnected electrical appliance, such as an 
outside air conditioner installation, into an improved service disconnect 
box. This resolves the problem of installing a separate outside 
weatherproofed service plug in a convenient location adjacent the 
electrical appliance where the service disconnect box is located. 
For initial installations the step of preparing a site, and interconnecting 
wiring from the service plug to the service disconnect box are eliminated 
to facilitate installation at lower cost of both electrician's time and 
the equipment necessary for provision of a service plug for the 
electrician to use when servicing the air conditioner. 
Similarly for retrofit installations the step of preparing a site and 
interconnecting the wiring is eliminated when the improved service 
disconnect box of this invention is available to replace the initially 
installed block with less electrician time and labor, which is a 
significant part of the installation cost. 
Thus, the improved service disconnect box has integrally mounted and wired 
therein the service plug accessory which the electrician may use when the 
air conditioner is disconnected from the source of electrical power, 
typically by manual removal of a plug by the servicing electrician when a 
cover access door is opened. 
The plug accessory in the service disconnect box can be configured and 
wired into service in several optional embodiments. One preferred 
embodiment has a ground fault electric service wiring connection from a 
power line source through a circuit protected by a breaker or fuse, 
typically of 15 or 20 ampere capacity, which connection is isolated from 
the incoming electrical power lines for powering the electrical appliance 
load, namely an air conditioner, or the like. 
Another embodiment has the auxiliary service plug wired from the incoming 
electrical power lines for powering the electrical appliance load, already 
provided for in routine prior art service disconnect boxes. This internal 
service disconnect box wiring optionally has either a full time live wired 
plug circuit connection or a plug circuit connection wired through a 
switch actuatued only when the disconnect plug is removed and there is no 
power available in the electrical appliance such as an air conditioner. 
Furthermore the auxiliary electrical plug circuit available for the 
electrician's use may be structurally mounted within the service 
disconnect box with access only when an access door is opened for the 
purpose of removing the disconnect link or block to disconnect the air 
conditioner. Alternatively the auxiliary electrical serviceman's plug may 
be mounted upon the box in a configuration protecting the plug for outside 
weather, but electrically connected whether or not the disconnect link is 
removed to remove electrical power from the electrical utility device. 
Other features, advantages and objectives of the invention will be found 
throughout the following specification, drawings and claims.

THE PREFERRED EMBODIMENTS 
Now with reference to the accompanying drawings, the state of the prior art 
disconnect box systems is seen from FIG. 1. The service disconnect box 15 
is mounted upon a building wall 16, typically masonry, to provide a safety 
disconnect link assuring that the electrical power from lines 17 to the 
air conditioner unit 18 is off when the electrician needs to service that 
unit. Thus the box 15 and the input appliance power lines 19 from a 
suitable source such as properly ground fault protected lines from a 
breaker or fuse box inside the building, are appropriately affixed to the 
wall 16 in accordance with the requirements of local electrical wiring 
codes. 
Since the disconnect box 15 isolates the air conditioner unit 18 from the 
possibility of having any live power lines therein, there is no electrical 
ac source of power for the servicing electrician to use in the servicing 
process to power instruments, tools, flashlights and the like. Thus, the 
electrician either needs to install on the wall 16 an electrical service 
socket outlet 20 in a convenient location for access when servicing the 
air conditioner unit 18, or to run a cable from some existing outside 
weather protected electrical service socket, or through a window, etc. 
from an inside-the-building electrical socket. 
The cost of installing the electrical service socket outlet 20 is high. 
Typically, in a brick wall 16, a mounting site must be prepared, possibly 
by a mason, and the incoming wires 20 must be connected from a remote fuse 
or breaker center, and the electrical outlet must be of the weatherproofed 
nature to withstand outdoor environment. Those problems are resolved by 
this invention, which as will later become evident facilitates the 
installation and reduces the equipment cost for supplying local electric 
service sockets at the air conditioner site for use of an electrician 
servicing the air conditioner. 
Now with reference to the structure of the service disconnect box 25 in 
FIG. 2 and the block electric circuit diagram of the service disconnect 
box wiring system of the FIG. 3 embodiment, the improvements of the 
disconnect box structure and electrical circuitry afforded by this 
invention are set forth. 
The improved electric service disconnect box for disconnecting electric 
power from an adjacent electrical appliance has structurally mounted 
thereon the electrical service output socket accessory mounted optionally 
either as internally mounted electrical socket 30, or externally mounted 
socket 30'. 
When the electrical socket accessory 30 is mounted, for example upon an 
internal panel 26 accessible inside the weatherproof housing 27 suitable 
for outdoor locations when the protective access cover 28 is manually 
opened and the typical disconnect plug 29 is removed to assure that there 
are no live power connections to the air conditioning unit 18. In this 
installation, the socket accessory 30 need not of itself be adapted to 
withstand the outside weather environment. 
The disadvantage of this internal configuration (30) of the electrical 
socket accessory, is that it cannot be used for any other use than as a 
service socket for repair of the air conditioner unit 18. Thus, the 
external configuration (30') provides the electrical socket accessory as a 
weatherproofed configuration located on an outer wall 31 of the service 
disconnect box 25, where it is available at all times for uses such as 
with electrical lawn trimmers, or the like. 
The internally disposed electrical circuit conduit means for conveying 
current from the appliance power line source 31 through incoming 
electrical supply wires 19 to output wires 17 in the embodiment of FIG. 3 
need not be modified, when the isolated power ground fault connected power 
line source 35 is connected into the service disconnect box 25 as shown at 
36. Note that preferably the electrical service socket accessory 30 is 
supplied with a local circuit breaker, reset by button 37. This isolated 
power line source 35 then becomes available for handling the power 
requirements of any servicing equipment used by the electrician during 
repairs and inspection of the air conditioner unit 18, without addition of 
current carrying capacity of the appliance power line source to handle 
surplus power above the peak load necessary to start an air conditioner 
compressor for example. 
In the FIG. 4 embodiment, the service socket accessory is mounted on the 
outside of the service disconnect box 25 cabinet walls, and is protected 
by a conventional weatherproofing cap for outside use. Either inside the 
service disconnect box or in the socket 30' assembly structure is mounted 
a fuse or breaker unit 40 for fusing protection of the service outlet 
socket. 
By way of bosses or wire connector terminals 41, the incoming power lines 
19 are branched to provide electrical connections within the disconnect 
box 25 to connect electrical wiring to power the electric socket accessory 
30' from said incoming electrical wiring 19 for powering the air 
conditioner, or other electrical appliance. 
One significant advantage of this embodiment is that to retrofit a service 
outlet socket 30 at an air conditioner site outside a building, for 
example, it may be quite inconvenient and expensive to find an 
installation site for an outside weatherproof socket accessory. This FIG. 
4 service disconnect box 25 as a unit therefore could be substituted for a 
conventional prior art type of disconnect box 15 (FIG. 1) with very little 
wiring and site preparation labor involved, thereby making it simpler to 
upgrade existing locations. 
In the fragmental view of the disconnect plug variation 29' of FIG. 5, a 
further embodiment of the invention is seen that comprises an electrical 
three ganged, double throw switch 50 is connected in said electrical 
connections between the incoming electrical wiring for said electrical 
appliance and the electrical plug accessory at the aforesaid terminals 
41', for example, thereby to connect electrical power to said electrical 
plug accessory only when the manual disconnect means is operable to 
disconnect power from the electrical appliance. The detent spring 51, or 
equivalent friction mount, holds the disconnect plug 29' normally in its 
stable downward position noted by arrowheads 52 to connect terminals 41' 
to the air conditioner for normal operation thereof. 
Conversely in the safety position, as shown, with the disconnect plug 29' 
pulled, the switch 50 is spring biassed to normally return to the 
uppermost position shown to connect the electrical power to the electrical 
service socket outlet accessory. Thus, the electrical service outlet can 
only be used to withdraw current from the appliance power line source (31) 
when the air conditioner is out of service. 
It is evident therefore from the foregoing specification that this 
invention has improved the state of the art. Accordingly those features of 
novelty believed representative of the spirit and nature of the invention 
are defined with particularity in the following claims.