Is a transfer switch needed if I don't have a generator on my camper?

[peculierboy]

I'm in the process of upgrading our electrical set up with an upgrade to Lithium batteries and a DC to DC charger and trying to sort out a few things. I'm upgrading the existing WFCO charger/converter to a Sterling Pro Charge Ultra for the new Lithium batteries and installing a Sterling DC to DC battery charger as well. I'm good on the DC to DC stuff as I'm doing vehicle to house charging already, but have a question on the AC side.

We have a Host truck camper and with no onboard generator. There is a WFCO T-30 Transfer Switch installed in our wiring loom. I'm wondering if it's ok to remove the transfer switch completely. Admittedly, I have not crawled into the basement to see how it's wired, but as far as I can guess, it was just installed and powers the power distribution panel. If that is the case, is there any reason why I can't just remove it and wire the panel direct? I'd like the wall space for the DC to DC unit.

We will never have an on board unit, and the few times we use our portable one, we just plug it into the shore power connection, there is no generator plug.

 

[DaveInDenver]

A transfer switch has nothing to do with the DC side. If you have a DC-to-AC inverter you'd need a transfer switch still.

It's to prevent a separately derived system (meaning something other than the main grid) that could be generating power and keeping circuits live when the electrician or user would expect it otherwise off after using a breaker.

You wouldn't need a transfer switch if you never plugged into shore power. The use of transfer switches is a code subject area so there may be applicable regulations that you have to follow.

 

[peculierboy]

@DaveInDenver Thanks for the reply. I think I mispoke on the ac to dc thing, my bad, sorry, should have been the ac connection. i edited my question to be clearer. We have an inverter, but it only powers two individual outlets that don't work when the inverter is off. If no shore power, the other outlets don't work at all. I think I need to crawl in there and trace the wires down to where they go.

 

[RAM5500 CAMPERTHING]

I'm no expert, but i believe you need it, IF connecting to shore power, so the inverter wouldnt feed of the batteries when plugged in.

If never connecting to shore power, it isnt needed

Some inverters (the victron multiplus for example) have the transfer switch completely built in and intergrated

 

[peculierboy]

@RAM5500 CAMPERTHING Thanks. That may be it. I'm trying to figure out why it's there, I can't imagine that Host would have put it in for no reason when a generator wasn't ordered even if it's only a $70 part.

 

[DaveInDenver]

Its simply a DPDT relay whats configured to default to ”generator input” whenever ”shore input” is not energised.

About the only real difference between a "proper" transfer switch and a simple DPDT relay is neutral and ground are considered with respect to Article 250. It might be simply showing in the manual how to wire it for safety and compliance or actually contain some sort of ground-neutral bonding bar or relay.

 

[SoCal Tom]

I don’t have a transfer switch, just an electric plug. If I want gen power I plug into a generator, if I want city power I plug in there. You only need a transfer switch if you have a generator hard wired.