Looking For Opinions On This Transfer Switch

[quickfarms]

a cheap way to do transfer, but does nothing for load management.

True

If you want to go with the interlock check with your panel manufacturer

Without going to an automatic set up there will be some power management involved. You can color code certain breakers to be turned off when the generator is used.

 

[CT-Mike]

I currently have a 5500w generator running to 30 amp Gentran panel, so it wouldn't be too hard to do what Ratch is suggesting. I'm thinking that is the way I will go. Something like this should do nicely:

http://t.homedepot.com/p/Eaton-100-...uble-Throw-Safety-Switch-DT223URH-N/100151733

I also plan to come up with a checklist for the wife on how to strip the emergency panel, start the generator, and then sequentially load the generator by closing breakers on the emergency panel largest load first and on down to the lighting.

Thanks for for the help guys.

 

[1800 Diesel]

I would not use that switch, the 50amp, with a 10kw genset for my house. It is a good way to control load, but with a 10kw generator that can overload to 13 or so, I'd use a 100amp switch minimum and maximize what you can get from it without tripping a breaker or potentially overheating the switch.
If you're willing to rewire your emergency circuits to that switch, you could get a standard service rated switch and a separate emergency panel. So you'd split your utility feed to two panels. One is normal loads, the other emergency. Put the switch between the split and the emergency panel.
I don't know if you can do all that for under $660, but used equipment is not bad if it works well.

I'm still sorting out all this transfer switch stuff myself, but I thought a generator transfer switch must be rated to handle your line service (which generally is 200 amps around here)--and by code the generator size is almost irrelevant. Please correct me if I am mistaken. I already have a Rink 100 amp transfer switch (donated by a family member) but my buddy who works for the power company told me the transfer switch had to at least match incoming service setup, which in our case is 200 amps...

Edit--A quick search turned this up:

http://www.steadypower.com/products...-(1Ph,-200A)&gclid=CNnFw5as5MMCFW0V7AodUjcA8w

This seems to be what I need., but still need to to a little more digging. For our MEP-004A I would specify the 25KW generator option to receive the correct item with a good margin allowance for amperage.

 

[PeterD]

There are many options. If you have not done so go to GarageJournal.com and search both the electrical forum, and the free parking one, and you'll see a lot of different methods.

 

[DieselAddict]

To look at it from a code compliance angle, there are a number of methods that will pass an electrical inspection.

The thing is to break it down is whether the transfer is automatic or manual. If the transfer method is MANUAL then it is assumed that the load management is also manual. In this scenario you can connect a generator that provides less power than the connected load can demand.

In contrast if you have an automatic transfer switch you may not connect more load than the capacity of the generator.

So the first decision is for automatic or manual transfer. From there you can made the next decision down the tree - transfer mehod.

 

[CT-Mike]

1800 Diesel,

This switch will be between my main panel and a sub-panel, with all emergency circuits moved to the sub-panel.

Hope this helps.

 

[DieselAddict]

Are you planning for a manual transfer switch?

 

[CT-Mike]

Are you planning for a manual transfer switch?

If you're asking me, yes, I am planning the 100A manual transfer switch I linked above.

 

[DieselAddict]

If you're asking me, yes, I am planning the 100A manual transfer switch I linked above.

Yep.. As long as the branch circuit is fused for 100a you can use a 100a manual transfer switch and overload the generator to your hearts content.

 

[CT-Mike]

I don't plan on overloading the generator at all. I am starting to work on an Arduino based monitor so that I can keep an eye on critical parameters from inside the house.

 

[DieselAddict]

I wouldn't expect you to do that. I'm just being silly on a Sunday morning.

 

[rhurey]

In contrast if you have an automatic transfer switch you may not connect more load than the capacity of the generator.

Unless you have load shedding, right? I've been looking at APC's load managing auto-transfer switches. Programmable load management and UPS integration. You could set it up so the lights never go off.

 

[DieselAddict]

Absolutely. If the transfer is automatic AND the load shed is automatic then you would still be in compliance.

 

[Ratch]

I'm still sorting out all this transfer switch stuff myself, but I thought a generator transfer switch must be rated to handle your line service (which generally is 200 amps around here)--and by code the generator size is almost irrelevant. Please correct me if I am mistaken. I already have a Rink 100 amp transfer switch (donated by a family member) but my buddy who works for the power company told me the transfer switch had to at least match incoming service setup, which in our case is 200 amps...

Edit--A quick search turned this up:

http://www.steadypower.com/products...-(1Ph,-200A)&gclid=CNnFw5as5MMCFW0V7AodUjcA8w

This seems to be what I need., but still need to to a little more digging. For our MEP-004A I would specify the 25KW generator option to receive the correct item with a good margin allowance for amperage.

If you were going to split your 200 amp utility feed to two panels, one normal and one emergency, you could then use a switch rated for whatever the split was. So if you made your normal panel 150 amp, you'd make the emergency panel 50 amp, and you could use a 50 amp transfer switch to supply the emergency panel. The switch has to be rated for the highest service that may pass through it.



If your 200a utility line needs to feed the emergency panel full-rated service, then the switch must be 200a. But if you're de-rating to a lower capacity emergency panel (let's say 50a), you'd stick a 50a disconnect before the switch, then a 50a breaker before the panel (or as the panel main breaker). You could use a 100a panel, but you could not use a 100a breaker before it, and would have to keep all load breakers under 50amps.







A good thing to remember is that your protection devices, like breakers and disconnects, should get lower and lower or stay the same as they get closer and closer to the load. Your wire capacity can always be higher rated than spec, but safety devices should be the same or never lower than spec, and never lower than the one before it in supply.

 

[1800 Diesel]

1800 Diesel,

This switch will be between my main panel and a sub-panel, with all emergency circuits moved to the sub-panel.

Hope this helps.

Understood--In my comment about the 200 amp-rated transfer switch I should have mentioned that I was planning to do a whole-house setup with no load management (except trying to keep the two legs loaded as equally as possible) and since the utility service has to pass through this switch before it gets to the main panel & sub panels that would be the scenario where the transfer switch had to be rated at whatever service you have coming in from the utility. So if I understand correctly, in your case, when you feed selected circuits instead of everything, then a lower rated transfer switch is allowed.