17 votes

Does the NEC allow a sub panel to be powered by a generator and an automatic transfer switch?

Sure, this isn't an issue What you're proposing isn't a problem at all from a Code standpoint. In fact, it's the normal way automatic transfer is done in facilities that have more complex power needs, ...
13 votes
Accepted

How much power can I supply for an EV charging circuit?

TLDR: Get a load-sensing energy monitor + EVSE pair, and allow them to automatically adjust your EV charge rate on the fly to protect your house from overload. EV charging is NOT a fixed rate, and ...
8 votes

Does the NEC allow a sub panel to be powered by a generator and an automatic transfer switch?

Don't add an empty subpanel just for new future loads. You should thoughtfully move some existing circuits to the new panel, leaving room in both panels for new future circuits. In the end the sub-...
  • 25.2k
7 votes
Accepted

Are these Challenger Type C breakers and panel safe?

but is this panel safe? Challenger panels are fine. Bryant picked up the bus design in the bankruptcy auction and used it for their BR line of panels, which is now Eaton BR. It's filled with a bunch ...
7 votes

What wire to use for 30Amp Dryer outlet 75 feet from the panel?

Use the size of breaker specified in the dryer instructions. It sounds like the whole dryer (heating element included) is 23A, which is absolutely typical and normal of 99% of dryers, since it ...
6 votes

40 amp breaker needs to upgrade to 50amp, do I need to change the wiring?

Breakers from 15A to 60A are priced the same. Therefore, the installer certainly used the largest breaker that is possible given the wiring they installed. In house wiring this is most likely 8 AWG ...
6 votes

Does the NEC allow a sub panel to be powered by a generator and an automatic transfer switch?

A 6KW generator is smallish and I DK if you could find one that is compatible with an ATS. Normally what happens when the power goes out, the ATS sends a signal to the generator to start, then it ...
6 votes

Does the NEC allow a sub panel to be powered by a generator and an automatic transfer switch?

First, if you're placing a subpanel near the main panel, I want you to run at least 5 conduits between the panels. If they're next to each other this amounts to short "nipples" they call ...
5 votes
Accepted

How to insulate the neutral from the ground in a Subpanel Siemens mc1020b1100sz

That is not a subpanel! That is a combination meter socket/main panel. By definition, that is the type of panel that always has neutral and ground bonded, so they don't give you the option of undoing ...
5 votes

What do I do when my main panel does not have a main disconnect?

There is no breaker in the meter. You have a Rule of 6 panel. I double-checked in the Schneider Electric web site and the datasheet specifically says "INSTALL NO MORE THAN SIX BREAKERS", ...
5 votes

Troubleshooting a dryer throwing a breaker

Actually, with a GFCI breaker, converting to 4-prong outlet is easy. 4-prong NEMA 14-30 socket. Connect ground to nothing! 4-prong dryer cord Install cord according to the instructions (separate ...
4 votes
Accepted

Backfeeding a main breaker panel

If it were me, I would put in a 100A main breaker, assuming one is available, save the 200A for the future and be done. This should be OK to do as you described. Devices to hold down branch breakers ...
4 votes
Accepted

Can I install a HEPD80 on a 40 amp 2-pole breaker

Yes, that's fine. If it is approved for a Type 1 insulation that means you could put it on a 10,000 amp breaker if you wanted to. Actually, Pushmatic terminals are UL-listed for 2 wires per breaker ...
4 votes

Can I install a HEPD80 on a 40 amp 2-pole breaker

The Installation Manual specifically says to use a 15, 20 or 30 amp 2-pole circuit breaker. Do not use a breaker larger than 30 amp.
4 votes

Connecting flush mount split service panels

Here's what I ended up doing. I knocked out two 1/2" knockouts in the bottom of each panel and fed the Sense Flex cable (this is low voltage) through those with some simple plastic bushings. I ...
  • 183
4 votes

Is it possible to switch my 100 amp main to a 200 amp main breaker And is there a 200amp breaker with 4 slots to run to 2 seperate sub panels?

Any main breaker panel will suffice All you need here is an outdoor (NEMA 3R rated) panel with a main breaker and a few breaker spaces. Your power comes into the main breaker, then goes out to the ...
4 votes

Is it possible to switch my 100 amp main to a 200 amp main breaker And is there a 200amp breaker with 4 slots to run to 2 seperate sub panels?

Can you upgrade service to 200A - ask your power company. There will be associated costs. If you split off from a 200A breaker you'd have to use 200A rated wiring from that breaker to smaller sub-...
  • 166k
4 votes

Which breaker controls the HVAC unit?

5/7 is labeled heat, but heat is actually a furnace of some sort which includes an air handler. That air handler is also used by the air conditioning on 2/4. To play it safe, turn both 2/4 and 5/7 off....
4 votes

Which breaker controls the HVAC unit?

In a rental unit you need permission from the landlord to do any work. Legally the landlord can make claim to any appliance you install on the building. To place a smart thermostat, you need to ...
3 votes
Accepted

How to measure (neutral wire) contact resistance/corrosion

The amount of work you'll have to do to measure it is greater than the amount of work to clean it up. So just take all the relevant points apart and visually inspect. Well, that's not quite true. The ...
3 votes
Accepted

30A double pole breaker has space on the panel but would only connect one circuit?

That panel comes in either a 6-space or 8-space variety. The person who bought this panel could've bought an 8-space. Instead, they bought a 6-space and a latté. I hope they really enjoyed that latté ...
3 votes
Accepted

What breaker size do I need to power radiant heat?

This sort of thing is normally done with two separate 20A circuits, where the load is 16A or less per circuit, but you have some oddball heat units just enough bigger (that extra 0.4A per heater) that ...
  • 166k
3 votes

How much power can I supply for an EV charging circuit?

There are online load calculators, such as this one. If your power company provides downloadable usage information, that can be a useful guide as well. Typically those provide either hourly or 15-...
3 votes

Is there a minimum height for the electrical disconnect to a small sub-panel?

There's a maximum height, NEC 404.8(a) - center of the grip of the operating handle not more than 2.0 meters (6'7") above floor level, but there is no minimum height defined in NEC. Possible but ...
  • 166k
3 votes
Accepted

Do wires connecting to an external electrical panel require outdoor rating?

A conduit which is outside, is outside. NM wire is not allowed in an outside conduit. NM cable does not like getting wet. The paper wadding will wick up water, where it will rot the wire insulation. ...
2 votes

How much power can I supply for an EV charging circuit?

Every domestic EVSE can be programmed to limit the amount of current they allow the car to draw. Smarter EVSE also have current probes that hook around the feeds of the panel to let the EVSE ...
2 votes
Accepted

MWBC and GE Spacesave dual-pole breaker spanning over different pole/phase

can I position a double-pole handle-tied switch to span over different phases, using a GE Spacesaver breaker? Actually, it's mandatory. NEC 110.3(B) requires you follow instructions and labeling. ...
2 votes

How to measure (neutral wire) contact resistance/corrosion

Directly measuring Ohms on power conductors is tricky, the resistance may not be ohmic - it may change depending on the voltage being used to measure it, also you have to turn the power off to make ...
  • 17.5k
2 votes

How to measure (neutral wire) contact resistance/corrosion

Resistance should be very low between any two points on your neutral and/or ground wires throughout the building. So low that a meter set to beep on items that are connected should always beep. ...
2 votes
Accepted

Lug for 250mcm neutral wire in Siemens panel

Use an ECLK3N According to Siemens' accessory guide for PN and SN panels, all 150A Siemens PN and SN panels save for the {P/S}NW0816BxxxT[C] feed-through ("ranch") panels can accept the ...

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