'Hot' testing with portable generator

[ichimo23]

I've noticed in a few threads that some of you will occasionally hot test with a portable generator. I dont have the luxury of temp power at some of the residential new construction jobs i do, and i was wondering what the best method is for hot testing with a generator. Do you send power thru the lugs to energize one phase of the panel, then test the individual circuits? If so, what is a safe and easy way to accomplish this? Thanks in advance for any tips

 

[brian john]

"HOT TEST" I assume you mean energizing the house wiring?

Why not test the circuits with a megger, I assume you intent is to verify the integrity of the wiring?

If you feel the need to energize the wiring, I would be SUPER careful, accidentally back feeding the utility is a possibility.

 

[growler]

I would be SUPER careful, accidentally back feeding the utility is a possibility.

I think the OP is asking how to test if the utilities are not hooked up at time of final.

If the utilities are hooked up then most areas will issue a temp. power release. This will allow the meter to be installed before final.

If the utilities are not hooked up I would normally connect a generator at the load side of the meter socket. With a 240 V generator it's easy to connect and check out the house. Unless you have a big generator you can't check out the AC units but you can make sure the wiring is good to the disconnect. It's safe enough because the generator has a breaker and if there are any shorts then the breaker on the generator will trip.

I don't have a big enough generator to power a range, water heater or AC units but I can take a meter and check for correct voltage at all disconnects and turn on all lights and check all receptacles. This lets you know that all wiring is good.

This is a common practice in many areas.

 

[brian john]

I think the OP is asking how to test if the utilities are not hooked up at time of final.

If the utilities are hooked up then most areas will issue a temp. power release. This will allow the meter to be installed before final.

I have seen many cases where utilities are installed, meter installed waiting on final connections at transformer.

If the utilities are not hooked up I would normally connect a generator at the load side of the meter socket. With a 240 V generator it's easy to connect and check out the house. Unless you have a big generator you can't check out the AC units but you can make sure the wiring is good to the disconnect. It's safe enough because the generator has a breaker and if there are any shorts then the breaker on the generator will trip.

I don't have a big enough generator to power a range, water heater or AC units but I can take a meter and check for correct voltage at all disconnects and turn on all lights and check all receptacles. This lets you know that all wiring is good.

This is a common practice in many areas.

Fair enough, I work in the end of the business where we test EVERYTHING prior to connection and STILL do not understand why someone would not megger everything first.

 

[C3PO]

Most of the inspectors around here want power on houses when they do their final inspections. If there is no power you can not verify that certain rec are GFI protected and things like that very easily.

 

[brian john]

STILL do not understand why someone would not megger everything first.

Does not address this question?

 

[satcom]

Does not address this question?

Just the way they do things today cheap and fast, most ot the production wiring is not tested at all, many years ago an electrician would not think of making the job hot, until it was meggered, and they even would put their name on it, today in most areas, we may have less then qualified help roughing a home, and most have not even heard of a megger or what it does.

 

[growler]

many years ago an electrician would not think of making the job hot, until it was meggered.

I learned to use a megger in 1974 and since then I have megged a few hundred miles of cable but I have never seen anyone take the time to meg evey branch circuit in residential new construction. If you see the service cable and service lateral megged that's about as good as it gets.

I have never seen every branch circuit megged in a high rise commercial building. All the heavy cables for the riser , service and feeders for panels but not every branch circuit. This keeps you from having an explosion but does not test all wiring. The only time that I have ever seen every cable in a building megged was for industrial and megging was required by job specs.

There has always been a cost factor to megging out every branch circuit that was not considered that important. :-? :-?

 

[satcom]

I learned to use a megger in 1974 and since then I have megged a few hundred miles of cable but I have never seen anyone take the time to meg evey branch circuit in residential new construction. If you see the service cable and service lateral megged that's about as good as it gets.

I have never seen every branch circuit megged in a high rise commercial building. All the heavy cables for the riser , service and feeders for panels but not every branch circuit. This keeps you from having an explosion but does not test all wiring. The only time that I have ever seen every cable in a building megged was for industrial and megging was required by job specs.

There has always been a cost factor to megging out every branch circuit that was not considered that important. :-? :-?

The megger testing in custom homes slowed down after the first Levittown, production homes were built in the 50's previous to that craftsman wired homes, then with production homes costs were cut to the bone, and quality was replaced with speed. Every once and a while we come across an older craft built home and some have plan sets with wiring schemes, and megger test readings along with the electricians name.

 

[Lxnxjxhx]

Rather than full voltage and current or a megger, you might put a 100w or larger bulb in series with a power source or across open breakers to test the new wiring.
If there's a short, it's no problem and it puts an amp or so through the wires for tracing purposes.
Heavy loads may light the bulb but the voltage into the Romex will still be higher than if it's seeing a short (a short at 1 A at the end of 50' of #12 Romex =~150 mV).

 

[glene77is]

'Hot' Testing

'Hot' Testing

to: Lxnxjxhx

The "Light Bulb Test Load" in the 'fuse panel'
was the method of choice at our company Virginia, in 1958!

glene77is

 

[Lxnxjxhx]

"Light Bulb Test Load"

"Light Bulb Test Load"

It worked for me. The customer miswired two three-way dimmers and, it turns out, fried one of them.
I didn't want to unpower the circuit and at some point I had to tell the difference between looking into a short and looking into the cold filament resistance of 600w worth of incandescents.
At a Hamfest I got a 100W 100 ohm rheostat that I use for this purpose. It's a little more predicatable than a lamp.