My MEP-803a experience

[lonesouth]

I was wrongly thinking that if switching a single leg of the 220, it would only see half of the load, i.e. half of the amps.

Any reason I should go with DPST instead of SPST? There is zero chance of me working on this when powered.

 

[Chrispyny]

Assuming the load is strictly 240v (120 per leg) and there is no neutral involved, placing a switch on one leg will be in essence turning the whole load on and off. So you would use a switch rated for the whole load.

In a 240v 2 leg circuit, each leg is 180° out of phase with the other. Try to imagine this analogy. Imagine a man on each leg. One pulling, one pushing, and they take turns 60 times a second. 2 men pushing and pulling together are stronger than 1 man pushing and pulling by himself.

A switch on one leg of a 240v circuit is in essence an open. No voltage will flow on either leg when the switch is open.

 

[lonesouth]

Thanks. Any reason to have more capacity than 20amp wall switches?

 

[Chrispyny]

Not really. Most appliances in america that require more than 20 amps at 120v are 240v anyway.

 

[lonesouth]

10-4. I may add a flow switch and relay to prevent the elements from turning on without water flow detected.

 

[DieselAddict]

10-4. I may add a flow switch and relay to prevent the elements from turning on without water flow detected.

I would highly recommend doing that!

 

[lonesouth]

got these home saturday. Got them unload yesterday. They are in good shape, 4 new walmart batteries, crank right up with good oil pressure, appear to generate power. I haven't put a load on them yet, but they respond as expected on the gauges.

I also picked up a 50 gallon fuel tank, new take off from a diesel shop, for $60.

Loading was a breeze. The GP rep had managed to get a milsup forklift running, and was able to lift the whole trailer and drop it exactly where it needed to go on mine. Unloading wasn't too eventful. I chained the genset to a tree and drove the yellow trailer out from under it. Now to unbolt the generators.


I managed a staggering 6.8mpg on the return trip @75mph.

 

[lonesouth]

4 or 6 gauge copper wire for running from the generator into the house panel(with interlock)?

60amp breaker for the generator?

 

[DieselAddict]

#4 or #6 would be appropriate for 60a depending on length. You are good on amps. Voltage drop ends up being the limitation as the leads get longer. #6 is good up to about 100' and #4 for over 100' and up to about 250'.

 

[lonesouth]

picked up 25' of 6/3 at lunch. This will be going next to my AC unit, provided there is room enough for maintenance.

 

[DieselAddict]

6/3 won't be code legal for a generator feed. You need to run a 4 wire cable.

 

[lonesouth]

maybe I have the terminology wrong, it is 3x6awg conductors and 1x8awg ground

http://www.lowes.com/pd/6-3-Indoor-Non-Metallic-Jacket-Wire-By-the-Foot/50101582

 

[DieselAddict]

You are OK with 6/3 w/ground.

Be sure to remove the ground/neutral bonding jumper at the generator.

 

[lonesouth]

will do.

 

[DieselAddict]

maybe I have the terminology wrong, it is 3x6awg conductors and 1x8awg ground

http://www.lowes.com/pd/6-3-Indoor-Non-Metallic-Jacket-Wire-By-the-Foot/50101582

FYI - That cable isn't rated to run between the generator and the structure. It is for indoor use only. You need a different kind of cable to run out to the generator.

Obviously it will function but it would fail an inspection.

 

[lonesouth]

inside conduit?

or do I have to use UF?

 

[DieselAddict]

Nope. You MAY be able to get away with that cable if its in conduit above ground (depending on the temperament of the inspector).

If you put the conduit below grade it is considered a wet location. You will need to use cable rated for wet locations. Sorry.

 

[lonesouth]

Better to do it right the first time. Thanks for the info.

 

[DieselAddict]

Totally agree. Sorry to have to give you that news.

 

[lonesouth]

Going to go with individual feeds and ground, instead of the UF. I think it should be easier to install.

http://www.lowes.com/pd/4-AWG-Stranded-Black-Copper-THHN-Wire-By-the-Foot/50101584

listed as approved for wet locations.