Lister Engine Forum

How to / DIY => Generators => Topic started by: Procrustes on August 06, 2006, 07:11:55 AM

Title: Transfer switch with no subpanel?
Post by: Procrustes on August 06, 2006, 07:11:55 AM
All but one of the transfer switches I know of involve separate electrical panels with a handful of emergency circuits plus a shuttle to select between grid power and genny power.  On one hand I see the the need for this, for instance with a smallish generator on an automatic transfer switch, or for someone who isn't familiar with the electrical system.  In these cases the subpanel guards against underpowering well pumps and such.  The "but one" involves an extension cord with two male ends and is not something I wish to pursue.

In my case the subpanel is a nuisance.  I'd rather shuttle between grid power and genny power without the subpanel.  My well pump is wired into the generator panel, but not the septic pump.  Therefore the well pump is really useful only up until the septic tank fills.  I'd much rather be able to pick and choose whichever circuits I want live.  Or if I end up with a big genny I could just flip a switch and have everything go on genny power.

Am I missing something, or is this something I should look into further?
Title: Re: Transfer switch with no subpanel?
Post by: Jackpine Savage on August 06, 2006, 12:59:20 PM
I have a similar situation and question. At my last farm I had one main transfer switch on the pole that would switch the whole farm between grid and generator power. If I wasn't milking the 50kw PTO genny could easily run the whole farm.

At our new place I would like to do the same but it's going to take some work because the pole is full. It has two meters and two subpanels hanging on it. I still want to fit a transfer switch in there so I can send genny power to the outbuildings, shop, etc. Then down the road I might also work in a battery bank and some solar.

I guess my question is though somewhere I read that code no longer allowed these main transfer switches. Does anyone know if that's the case for sure? 
Title: Re: Transfer switch with no subpanel?
Post by: Tugger on August 06, 2006, 03:26:25 PM
On the counter at my local electrical wholesaler is a new unit just CSA approved that plugs inbetween your meter and the meterbase.....
You pull out the meter....meter plugs into tranfer switch.....then transfer switch plugs into the meter socket....you local electrical inspector will need to inspect it also...
There is a outlet on the side of the transfer switch that the generator plugs into...

This will not work for centeral metering....

price...wholesale...you dont get alot of change from $1000.00 cdn.
Title: Re: Transfer switch with no subpanel?
Post by: Johnm49 on August 14, 2006, 01:45:39 PM
A manual transfer switch is acceptable to use. They are used on many large size installs where the entire facility is to be feed from utility power or a generator. Some installs such a hospital will have sub panels of critical needed circuits that are connected to a transfer switch and the switch will feed only the sub panels to cut down on the load that the generator needs to provide. The utility power comes into the building and directly to the transfer switch. From there you chose what source of power you want to feed your panel. There are manual or automatic switches from 60 amp to 1000+++ amp switches.
Title: Re: Transfer switch with no subpanel?
Post by: ramdiesel3500 on August 17, 2006, 03:36:02 PM
Hello
I have been following this forum for some time now.  I do not (yet) own an lister type engine.  However, I am a self proclaimed "diesel head" and I also earn my living as an engineer in the electrical contracting industry.  I have done extensive work with generator and transfer switch systems.  Installing a manual transfer switch for your whole house is not an uncommon thing.  In fact, I have my entire home and shop fed from a single 200A single phase service.  The service is routed through a 200A manual transfer switch.  When we experience a power outage, I go to my house power panel first and shut off all non-essential high power circuit breakers (clothes dryer, hot tub, wall oven, A/C condenser, water heater) and I turn off all breakers feeding motor loads (refrigerator, well pump, septic pump, freezer). Then I go get the generator and roll it over to the transfer switch.  I have a cord connected to the generator terminals of the switch with a plug on the other end.  I plug the cord into the generator, start the generator, and then flip the manual switch.  By flipping the switch I disconnect the house from the utility grid and connect the house to the generator.  Finally, I go back to my house power panel and turn on all the motor loads one-at-a-time.  This way, I do not overload the generator by trying to start several motors at once.  I am actually able to run my 2200 sq. ft home with my little 5kw generator.  I just cannot run things like A/C, clothes dryer, electric water heater(water heater can be operated if I shut off everything else), oven, and any other load that exceeds the 5000 watt capability.  It sure is nice, during a utility outage, to be able to watch tv, have running water, have the use of every light fixture and electrical outlet in the house, run the furnace blower for heat, etc.  Also, some day I may purchase a larger generator so I can operate more of my larger power appliances.  The switch is large enough for this, so I only need a larger generator and larger power cord/plug.
Take care!
Title: Re: Transfer switch with no subpanel?
Post by: Procrustes on August 17, 2006, 08:45:22 PM
Thanks ramdiesel3500 and Johnm49.  That's exactly what I wanted to know.

Now if I can just figure out how to run my single phase 200A line through a switch without getting fried...
Title: Re: Transfer switch with no subpanel?
Post by: ramdiesel3500 on August 18, 2006, 01:48:47 PM
When I set up my switch, I asked the utility provider to pull my meter and kill power at the transformer.  Then I was able to work it de-energized (the only real safe way).  Nice thing about this was that when I finished my part of the work, I just fired up the generator and ran on gen power until the Utility Co. was able to come back out and turn everything back on!  I have installed transfer switches for customers to feed sub-panels.  But mine is the only service switch I have done.  Power in my region is very reliable for the most part.  However, I live in a heavily wooded area on the end of a very long utility MV circuit.  So we have lots more outages than most of the folks here.  I set a 200A enclosed breaker for my service entrance.  From the breaker, I fed the transfer switch utility lugs.  I then fed a 200A main lug panel from the common load terminals of the transfer switch.  Works great!  Good luck with your installation!
Title: Re: Transfer switch with no subpanel?
Post by: Rainbow-Farm on August 30, 2006, 04:41:28 PM
Procrustes, I also live in Canada, and was told by a generator supplier that the whole-panel box sells for about $1,000. for a 100-amp service and about $200 more for a 200-amp service/panel. These are to code in Ontario. In NY, I have seen transfer boxes, whole-house, from about $300 US, but not sure whether they are "legal" or even safe here.

I agree that switching the whole thing is much simpler, and then selecting the loads yourself. If you run too much stuff, you will know about it soon enough. Something will not run well (usually a motor or pump), or your engine will complain audibly or visually.

Title: Re: Transfer switch with no subpanel?
Post by: buickanddeere on September 02, 2006, 09:53:14 PM
  Installing a sub-panel or emergency panel to connect a generator is good $$$ for us electricians on a cold rainy or snowy day.
  An auto or manual tranasfer switch to connet the entire service only to the grid or only to the generator is the way to go. Reliance Controls makes several different types of indoor and outdoor transfer main switches and transfer breaker panels. Ronk makes a comination hydro meter base and transfer switch/generator connection.
  You will never regret doing the job right. Saving the money by avoiding a sub-panel and spend the coin instead going a size bigger on the generator then just use a cheap simple transfer switch on the mains instead.
  If the wife can't resisit turning on the clothes drier or the entire stove while the AC is running, let sit and sweator freeze in the dark a few times after she overloads the system. "Cause and effect" will register after some time.
  For those in Canada and with people in the hous ethat don't understand load shedding. Use a 68 circuit FPE transfer panel. Put the lights, microwave, well pump on the bottom utility/generator breakers. And tie the kitchen stove, clothes dryer etc into the top 44 utility only circuits.