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Help me pick a 3 pole double throw switch.

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Patrick1

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Could some one be kind enough to help me out picking the "right" manual transfer switch?

I would like to have a manual 3 pole double throw transfer switch that switches to neutral.
It will be installed inside the designated "Inverters Room".
I am planning to leave the grounding screws of the inverters in.
The inverters will be in split phase (240V).

How many amps should it be?
Do I need fused or non-fused?

My equipment:
2 EG4 6500ex + 6 Racked Batteries (EG4 LL 48V version1)

Oh, forgot to mention, I will be connecting Utility AC to charge batteries if needed.
 
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Can any one also tell me how do I know when a 3 pole double thrown transfer switch transfers neutrals?

I was looking at Siemens NF322DTK but I could not see in the specs anything about switching to neutral.

​

 
Patrick1 said:
Can any one also tell me how do I know when a 3 pole double thrown transfer switch transfers neutrals?

I was looking at Siemens NF322DTK but I could not see in the specs anything about switching to neutral.
Click to expand...
Without a diagram of your system it is difficult to be specific. Generally, there is nothing magical about the neutral, it can be treated like any of the other current carrying conductors. Likewise each POLE of the double throw switch is independent and isolated from the others.
If you have a standard US 240V/120V split phase system with 2 hot wires and 1 neutral then the 3 pole transfer switch is all you need, just use one of the poles for the neutral. If you have a 3 phase system with neutral then you will need a 4 pole transfer switch.
 
As of now, this is what I am planning...

Option4.png
According to an electrician I have 100A service, but the breakers at the meter box say 125A.
If the electrician is right, a 100A 3 pole double throw switch should be fine.
Right?
I asked because, I read the comments at HomeDepot where someone asked , and the
answer was that they will have to get a 200A TS with the similar 125A service.

Any opinions on fused vs "non-fused"?
 
If the circuit breaker is rated for 125A then everything it protects must be rated at least as high or higher. In this case there are 3 options.
1) Get a 100Amp non-fused safety switch and downgrade the main breaker to 100Amps if that is an option based on your electrical requirements. This would be my choice because its simpler, there is still just one CB and no fuses to go bad. There is a cost associated with a new main breaker although there are sources for good, refurbished and tested breakers available.
2) Get a 100Amp Fused safety switch and use 100A fuses. Introduces extra components that can fail and there is added cost for both the disconnect and the fuses which may be about the same as if the main breaker were replaced. Again this is based on your electrical requirements as to the feasibility of downgrading to 100A.
3) Get a 200A non-fused safety switch. This is going to be expensive.
 
Patrick1 said:
As of now, this is what I am planning...

View attachment 127559
According to an electrician I have 100A service, but the breakers at the meter box say 125A.
If the electrician is right, a 100A 3 pole double throw switch should be fine.
Right?
I asked because, I read the comments at HomeDepot where someone asked , and the
answer was that they will have to get a 200A TS with the similar 125A service.

Any opinions on fused vs "non-fused"?
Click to expand...
Well that scares me…. House panel no grounds? Done thru where?
 
BentleyJ said:
If the circuit breaker is rated for 125A then everything it protects must be rated at least as high or higher. In this case there are 3 options.
1) Get a 100Amp non-fused safety switch and downgrade the main breaker to 100Amps if that is an option based on your electrical requirements. This would be my choice because its simpler, there is still just one CB and no fuses to go bad. There is a cost associated with a new main breaker although there are sources for good, refurbished and tested breakers available.
2) Get a 100Amp Fused safety switch and use 100A fuses. Introduces extra components that can fail and there is added cost for both the disconnect and the fuses which may be about the same as if the main breaker were replaced. Again this is based on your electrical requirements as to the feasibility of downgrading to 100A.
3) Get a 200A non-fused safety switch. This is going to be expensive.
Click to expand...
Your first suggestion will need to be done by an electrician, correct?
 
Patrick1 said:
Your first suggestion will need to be done by an electrician, correct?
Click to expand...
Either the meter has to be removed or the wires on the line side of the main breaker have to be worked while live. I've done it both ways. Once by removing the super secret barrel locking mechanism without causing any visible damage to the exterior of the meter base or ring and once by taking one live wire out of the breaker lug at a time and putting an insulated polaris connector on the wire so I could work fairly safely in the main panel with the main wires hanging but not exposed. Don't recommend either way for anyone not super comfortable doing it themselves.
 
EATON DT323NDK, it's considered a 4 pole but one pole isn't switched.

Rated for 100A, I own one. Currently have a 60A 3 pole in.
 
here is a pic of my AC side with a transfer switch I got off of ebay

Grid-transfer-switch-to-panel.jpg

Grid box incoming on upper left. A 60 amp breaker goes down to the 3 pole transfer switch.
another 60 amp breaker leaves the Grid box on its right and provides Inverter GRID IN

Transfer switch provides switching between GRID from above and Inverter OUT from below
Its center tap output then feeds to the Critical Loads Service Panel on the right, which feeds most of the house and out building. See line diagram in post below

The transfer switch is a 60amp 240v 3 pole double throw

and then a pic of the the XW Pro inverter to the right of the Critical Loads Service Panel

panel and XWPro.jpg
 
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That 60A double throw switch is perfect for the XW Pro. May I ask what brand and model number it is? Don't recall seeing that item when I was searching the other day, looks really compact compared to others.
 
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