installing non-automatic transfer switch
I have questions about installing a Gen-Tran, 30 amp, non-automatic transfer switch, #301660, just to the right of two, C-H 200 amp service panels(400 amp service) on my basement concrete wall. My 60 amp feeder breaker goes in the right service panel. I want to provide emergency service to my 240V, 20 amp well pump and 120V, 20 amp furnace circuits, currently wired to the right panel, and to my 20 amp small appliance/refrigerator circuit and 15 amp bathroom lighting/ventilation circuit, currently wired to the left. My questions are:
1. Should I splice the neutrals of the circuits in the left panel to the neutral/ground bar in the right panel which contains the feeder breaker?
2. Can I leave disconnected circuit breakers in the service panels in place?
3. Must the spliced conductors from the service panels to the transfer switch be marked?
4. Do the four emergency circuits overload my 30 amp transfer switch by code? How do I calculate the load for eating area small appliances in the small appliance circuit below?
Well pump full-load current = 6.9 amp(Table 430.248).
Furnace full-load current = 13.8 amp(Table 430.248); EIM(controller) = 0.2-1.0 running
amps specified in installation manual.
Small appliance circuit: refrigerator label load current = 7.2 amp[440.6(A)]; 13 – 115V
duplex receptacle outlets for eating area small appliances = ? amps by code.
Bathroom lighting/ventilation circuit: 7 fixtures with fluorescent bulbs = 1.2 amp; 2
ventilation fans = 1.8 amp; 3 – 115V duplex, general use receptacle outlets = 0
5. For the branch circuits, does code require calculation of allowable ampacity of the spliced conductors from the service panels to the transfer switch, or can I use the 90°(THHN) #12 AWG provided by Gen-Tran? Existing wiring is NM-B, 12-2G for the 20 amp circuits and 14-2 for the bathroom circuit.
6. For calculating allowable ampacity of the 90°(THHN) #6 AWG conductors provided by Gen-Tran for the 60 amp feeder service from the right service panel, what ambient temperature correction factor should I apply to the allowable ampacity in Table 310.15(B)(16)?
7. Must I connect my portable generator's ground lug to an earth ground? If so, what is the best way? I have outdoor access to my home's ground electrode and steel wellhead.
8. Is flush-mounting a Reliance power inlet box to the sheetrock interior wall of my garage about 12” above the slab okay? Only the cap will protrude about 1” from the wall.
9. What areas of the NEC will the test allowing homeowner installation likely cover?
Thanks for whatever help you can provide.
thanks; some final questions
Thank you much for your answers and advice.
In regard to moving emergency powered circuits into one main panel holding the feeder breaker:
Existing circuit wiring would require me to extend the NM-B for at least one circuit using a
junction box, I guess. Would it also be acceptable to:
1) splice the circuit neutrals to the separated neutral bar in the transfer switch, and
connect the bar with a white insulated conductor to one of the bonded neutral/ground bars in the right main panel holding the feeder breaker;
2) splice the circuit grounding wires of the two circuits in the left main panel to one of the neutral/ground bars in the right panel or to the ground bar in the transfer
switch, and connect the ground bar with a green insulated conductor to one of the neutral/ground bars in the right panel; and,
3) splice the circuit load conductors to the circuit breakers in the transfer switch?
In regard to your discussion of the generator's capacity, particularly with respect to the well pump, I should have provided the following in my original post:
My generator is a Honeywell HW7500E. The Owner's Manual lists Surge Power =
11250W, Maximum Power = 9375W, and Continuous (Rated) Power = 7500W.
My well pump is a Goulds ¾ HP. The label for the Franklin-Electric motor in the well pump lists s.f. Max amp = 8.0 amp. For what it's worth, the owner of the company which installed the pump told me that start pulls 16.5 to 18 amps and recommends a 20 amp breaker. But, Goulds, lists in online specifications a 20 amp breaker and a starting(surge) load of 9400W. The existing breaker in the main panel is a 25 amp.
I noticed the agreement between you and jwelectric in warning me about the danger to my electronics and the danger of stalling the generator. I will type up guidelines for avoiding use of plug-in electronics, for opening circuit breakers in the transfer switch before throwing the interlocked feeder breakers, and procedures for avoiding simultaneous starting of the well pump and blower motors. I will post the guidelines with appropriate warning symbols on the transfer switch cover.
One last question: I would like to install the power inlet on an outside wall at least several feet above grade in order to minimize wetness from snow. (My inlet is a Reliance PB30 with a horizontal plug.) At this height, my garage wall provides the easiest access to my basement through the use of an interior run of 4-wire #10 cable on the inside of the wall. What type of cable/conduit, attachment, and wall penetration devices would you recommend? The cable would turn 90° to enter the basement parallel to an end joist resting on the basement wall to which the panels are attached, and would have a run of 7' before dropping to the transfer switch.
I can't thank you and jwelectric enough for your generous advice.