Electrical Advice?

[Ken Fitzgerald]

I need to buy the service entry components for my new shop this week. I been look at Square D "QO" line, Murray and Cutler Hammer 240v, 200amp service panels. The Murray has copper bus.......the Square D and the Cutler Hammer have tin coated copper buses for "corrosion prevention" reasons. Anybody have any thoughts or advice as to which might be a better 200 amp service panel?

[Dean Baumgartner]

I have the Square D QO series in my shop. My electrician reccomended it. Square D QO is also pretty much the standard for all of the 120V stuff that the electrical engineers at work use for industrial applications so it must be pretty decent stuff.

[Todd Burch]

Price the breakers that you'll be using. I had GE at my last place, and Cutler Hammer in my current place. Both seems OK - and they are NOT interchangeable. Your main breaker will be the most costly. I know Cutler Hammer has "double" (1/2 size) breakers. But, with 200 amp service just for the shop, that probably won't be a concern for you!

Be sure to run that 50 amp branch for the welder you might not have yet!

[Wes Bischel]

Ken,

My main panel is Cutler Hammer, and my aux. panel in the garage is GE. The were put in about 10 years ago and I will say the Cutler products just fit together better. Not that the GE hasn't performed over the years, it's just that the GE was noticably sloppy when compared to the Cutler breakers.

Todd brings up a really important point concerning the breakers. You don't want to be surprised. Also, check with your local electrical suppliers - some will give you a package deal box breakers etc.

FWIW, Wes

[Tyler Howell]

Ken,
Square D is the industry standard. Can always find parts (breakers) reasonably priced everywhere.

[Frank Pellow]

I did lots of research and recieved lots of advise about the panel to use in my shop. I am going to go with the SquareD "QO" series.

[Dan Mages]

My grandfather sold Square D breakers in his hardware store. I also reccomend investing $30-$40 on a panel surge protector. It will handle upwards of 40,000 joules of surge protection. It is cheap insurance for your power tools.

Dan

[Rob Russell]

Ken,

The SquareD QOD (vs. Homeline) series of panels and breakers is what some consider an industry standard. The QOB-series panels (B for bolt-on breakers) are widely used in industrial applications.

Our house has all GE panels. Had I thought about it, when I upgraded our main service to 200 amp, I would have paid the extra for the SqD, but I already had a GE sub running off of the old panels and planned to reuse it. I sort of wish I'd gone with the SqD and Ebay'd the older GE stuff. I'm solidly locked into the GE breakers now for all the "normal" wiring, although my 3-phase panel is SqD.

One difference you'll note is that the SqD breakers snap on to the buss bars more solidly. I can wiggle my GE breakers from side to side. You can't do that with the SqD. Make sure you get a full 42 slot panel.

It's also worth, in my mind, upsizing your conductors 1 gauge, even after you've figured in voltage drop based on distance when you run the wire to provide extra current-carrying head room. I can't provide a really rational reason for oversizing the conductors, other than preference. Either way, the conductors carrying your 200 amp service to the shop are gonna be big ones (4/0 or 250 MCM). I'm assuming that this is a separate service and not a subpanel off of your house service. BTW, if you have the ability to so, consider running 3-phase to the shop. It would give you the ability to buy machinery that's a whole class different for cheap. You could either go with really nice stuff (Felder, big MiniMax) or get surplus industrial (Unisaw/PM66) at auction with 3-phase motors for 30-40% less than 240v single phase. You still have normal 120v for all your regular circuits.

You may want to invest in a "main lug" panel and separate 200 amp disconnect switch vs. main breaker panel so you can completely power down the panel to work on it. YMMV.

Rob

[Chris Padilla]

Hey Rob,

I was poking around the main feed (with a metal screwdriver held in my mouth! :eek: ) and noticed I have 2 AWG aluminum wires heading towards the meter. The mains are 150 A breakers. Does this mean I have "150 amp service" into my house? My house was built in 1973 so it isn't all that old. Would I contact PG&E (Pacific Gas and Electric, the utility company) to determine if they would bring 3 phase into my house?

[Robert Ducharme]

From a non-electrician.

If your main breaker is 150 A, then you have a 150 service. It bothers me that your wires coming in are 2 AWG Aluminum. That seems a little thin - especially since they are not copper.

[Rob Russell]

I was poking around the main feed (with a metal screwdriver held in my mouth! :eek: ) ...

Stranger things have happened! :D



I ... noticed I have 2 AWG aluminum wires heading towards the meter. The mains are 150 A breakers. Does this mean I have "150 amp service" into my house?

I hope you don't have a 150 amp main breaker with 2 AWG aluminum conductors. 2 AWG conductors, as service feeders, are rated for 100 amps. In typical branch circuit wiring they're rated for 90 amps (at 75*C). I could believe you have 2/0 AWG aluminum conductors. Those have a service feeder rating of 150 amps.

If you have a 150-amp main breaker, it does indeed sound as if you have 150 amp service.



Would I contact PG&E (Pacific Gas and Electric, the utility company) to determine if they would bring 3 phase into my house?

Yep. FYI, the key thing to getting 3-phase service cheap is whether it's on the pole or pad-mount transformer that feeds your house. If not, you're talking BIG bucks to get 3-phase because the LOPOCO needs to run it from the nearest source. If, as in my neighborhood, that means digging up underground lines it costs even more. That's why I've gone the rotary phase convertor (RPC) route.

[threadjack]
As a slight tangent, I may have another problem. If, when I fire up the RPC, my neighbors' light dim too because of the idler motor's startup current demand, I'll have to either use a "low-current" way to start the RPC (means a PITA to me) or pay for a separate transformer drop. As wild as it seems, a small transformer right next to our house isn't that crazy an idea. It would take the 15kv high voltage power and produce normal 120/240 but we'd be the only folks hitting that transformer. Sorta like getting a hookup to the fire hydrant to water your lawn. I hope I don't have to deal with that issue.
[\threadjack]

As another comment about 3-phase power, if it is available, you need to see what kind it is. For a residential setting, 3-phase delta ("wild leg") works best because you still get normal single-phase 240v capability for your appliances. If it's 120/208 Y 3-phase, your 240v dryer and stove won't run as hot, nor would normal 240v tools.

Rob

[Chris Padilla]

My bad...it is 2/0. Thanks for the info as always! :D

[Dennis Peacock]

I checked on getting 3 Phase power to my house / shop. I would have to purchase 2 power poles and a transformer and then they would have to run the lines from the nearest 3 phase power station, about 1/2 mile away. Total cost? A mere $15,000.00 :eek: ...Needless to say....I'm still on single phase power.:D

[Rob Russell]

I checked on getting 3 Phase power to my house / shop. I would have to purchase 2 power poles and a transformer and then they would have to run the lines from the nearest 3 phase power station, about 1/2 mile away. Total cost? A mere $15,000.00 :eek: ...Needless to say....I'm still on single phase power.:D

Dennis,

We're about 1/4 mile off of a numbered state route and I have to believe there is 3-phase on that road (large restaurant close by). The huge cost for us would have been the excavation of everything from that road into our neighborhood, plus transformer cost, plus ..., plus ...

I had talked with the LOPOCO engineer about this and, while he never gave me an estimate, I'd bet it's in the $50-100K range because of the digging.

To use your phrese, "Needless to say" - we're still fed only single phase power!

Rob

[jim barter]

Ken / If you install a 3 phase service to your shop don't forget that any 240 volt rated motors(compressor) most likely will burn up as the highest voltage that you will recieve from the utility is 208 volts.In New Brunswick, Canada 3 phase is not allowed for a premise but ok for a shop.I live in a rural area and we do not have three phase on our road.As far as a wild or high leg this is dangerous as the voltage on one phase to ground could possibly be as high as 180 volts. If you mistakenly tie say a lighting circuit to this leg you will smoke ballast,lamps etc.Stick with 120/240 volts in my opinion. I'm a provincial electrical inspector and deal with the public buyuing 240 volt equipment all the time and find later that it can't handle the lower voltage

[Ken Fitzgerald]

Jim, thanks for the advice. I will be using 120/240. The additional cost would be more than my budget would allow. :D