HVAC-Talk: Heating, Air & Refrigeration Discussion - Open Discussion Electrical

Neat NCV trick

Core_d — Sat, 15 Jun 2013 17:26:05 GMT

Next time you have your NCV handy grab hold of the insulated portion of a hot wire or hot and neutral extension cord(works either way) with one hand and test your nearest partner with your NCV in the other hand. Lol wow hes hot. Its a neat trick any insight on the subject?

30 amp receptacle for 5000 watt generator

hvacques1 — Fri, 14 Jun 2013 18:58:30 GMT

This may be a dumb question....but I am considering buying a backup generator which has a max output of 5000 watts, and running it to a transfer switch (for use with only 120 volt circuits). I noticed that the main receptacle on the generator (the receptacle that would be used with the transfer switch) is 3-pronged and rated 30 amps/125volts. Wouldn't that limit the usable generator output to approx 3750 amps, wasting the remaining capacity of the generator? Or is there something I do not understand?

Thank you!!!!

How are ground fault mini-breakers wired ? Are they even mini-breakers at all?

Poodle Head Mikey — Mon, 10 Jun 2013 18:05:58 GMT

This breaker is single-pole-sized and appears to only snap onto one buss bar in the panel. It had one full-sized single pole breaker looking 'switching handle' on it.

But . . . it has two screw terminals - and so in that regard looks like the output end of a mini-breaker.

Under the twin screw load side terminals there is a white wire coming out. This lone white wire goes to the neutral/ground connection terminal buss.

There is a freezer drain line heater wired to this breaker. Both sides of the drain line circuit are wired to the two terminals on the breaker. This seems like it cannot possibly work as the potential would be the same on both sides of the circuit.

Ahhhhh . . . . but it Does work - apparently because only one of the breaker's screw terminals have power.

So anyway: wth am I looking at here? Is there supposed to be the same power from each of the output screw terminals? That is: 120 VAC to neutral? Mini breaker fashion?

Or . . . . is the second terminal actually a common connection - being made through that white wire going to the neutral/ground bar?

So? How do it work?

wiring question

brodie123 — Fri, 24 May 2013 22:48:15 GMT

Hi All;

We are trying to install a new furnace fan motor. The new unit is a marathon electric CAT NO B208.

115V single phase AC motor

There is a wiring diagram, but seems incomplete. I've search their site for wiring an cannot find any.

The wiring refers to red and black only, and shows you which post to put them on for CW or CCW. (we want CCW - so we reverse them as per the diagram).

Can you please indicate the rest of the wiring? I don't want to fry the motor getting it wrong.

The remaining wires are Blue and Yellow.

Thank you in advance.

tell me it aint so!!!

02JeepKing — Fri, 24 May 2013 01:04:40 GMT

On a recent callout i found all the low volt components burnt. Carrier 5 ton heat pump with a bad transformer and contacor in air handler, blown relays in thermostat (2 weeks old) on cooling only(heat and fan relays work) and in condenser i found the defrost control board burnt, the contactor coil burnt, and reversing valve solenoid burnt. all components have been replaced except the solenoid. The valve must be replaced. the system can be made to run in the heat mode but the root cause has not been determined. please help!!!!