Rewire converter for transfer switch.

[Hewster]

Wiring in an EMS and transfer switch for my inverter/shore power.

My plan is wire in EMS so it will be protecting the system on the shore power cable/generator side.

Other side of transfer switch will have inverter input.

To eliminate the converter running when inverter is powering unit I’m planning on moving wiring and tying in with shore power on the transfer switch.

Anyone else done this? Tips? Ideas?

Yes I can just turn the breaker off but trying to make it more automatic and user friendly for when I’m out of town working and my wife and kids want to go out camping.

 

[Gary RV_Wizard]

If you combine generator & shore cable on one side of the transfer switch, how do you prevent generator from conflicting with shore power? If the two were ever active at the same time, nasty things will almost surely happen! The entire purpose of the transfer switch is to prevent that.

A rough sketch of the planned wiring would be helpful in understanding your plan.

 

[Hewster]

If you combine generator & shore cable on one side of the transfer switch, how do you prevent generator from conflicting with shore power? If the two were ever active at the same time, nasty things will almost surely happen! The entire purpose of the transfer switch is to prevent that.

Conflict between shore and generator won’t be an issue, it’ll be only ever 1 or the other.

Never shore and generator at same time. Only generator/inverter ( boo docking is most of our camping)

 

[Lou Schneider]

How will you keep the shore power or generator seperate? You can't have both connected at the same time even if one is off. You'll need either a second automatic transfer switch to choose between them or the manual version, a single plug you can connect either to shore power or the generator but not both.

Put the converter on the shore power input side of the transfer switch. You'll need a 15 amp fuse or circuit breaker in line with the converter to limit the current to a safe value in case of a short.

 

[SuwanneeDave]

How will you keep shore power or generator seperate? You can't have both connected at the same time even if one is off. You'll need a second automatic transfer switch or the manual version, a single plug you can plug into either shore power or the generator.

I don't think he is talking about an onboard generator. He would either be plugged into shore power or plugged into his generator

 

[Hewster]

It’s a 30 amp keystone Springdale.

There will never be shore and generator at the same time. It’ll only ever be one or the other.

If we use shore then generator isn’t used. If we use generator then we’re boomdocking and shore isn’t even available.

 

[Hewster]

I don't think he is talking about an onboard generator. He would either be plugged into shore power or plugged into his generator

100% correct.

Portable Honda gen set, not an onboard unit. Never shore power and generator at the same time.

 

[JayArr]

So you have an inverter, a generator and a converter? and you want a transfer switch between the shore power and the inverter.

Yes, run the converter to the shore power side of the switch but if you are rewiring you should also remove your air con line from your fusebox and run it to the shore power as well. This will ensure that you never accidentally try to run your air conditioner from the inverter. Make sure you put a fuse or breaker on each of these lines so you don't burn your trailer down.

An EMS may cause problems if applied to the genny, you have to know what you're doing in regards to grounding and frame bonding etc or the EMS unit will give false errors. There have been several threads in the last year where people have had this problem and have sorted it out, do some reading.

I would recommend an external EMS that could be used for shore power but not used with the genny.

 

[Hewster]

So you have an inverter, a generator and a converter? and you want a transfer switch between the shore power and the inverter.

Yes, run the converter to the shore power side of the switch but if you are rewiring you should also remove your air con line from your fusebox and run it to the shore power as well. This will ensure that you never accidentally try to run your air conditioner from the inverter. Make sure you put a fuse or breaker on each of these lines so you don't burn your trailer down.

Will you have another switch between the shore power and genny or do you just plug your shore power line into a portable genny?

An EMS may cause problems if applied to the genny, you have to know what you're doing in regards to grounding and frame bonding etc or the EMS unit will give false errors. There have been several threads in the last year where people have had this problem and have sorted it out, do some reading.

If you plug your shore power into a portable genny then I would recommend an external EMS that could be used for shore power but not used with the genny.

Yes I plan as of right now to wire it to the shore power side, in-line fuse/breaker to the converter for protection.
- I’m not worried about the AC or microwave so much as the wife is very good about knowing not to use those when on inverter.

- no switch between genny and shore power as they’ll never be used at the same time, yes I physically plug my shore power cord into the generator. It’s not an on board unit either.

- I have a neutral bonding plug for use with my Honda 2200/2000 for use with the EMS and also have a bypass switch for it if needed.

 

[Lou Schneider]

Yes I plan as of right now to wire it to the shore power side, in-line fuse/breaker to the converter for protection.
- I’m not worried about the AC or microwave so much as the wife is very good about knowing not to use those when on inverter.

- no switch between genny and shore power as they’ll never be used at the same time, yes I physically plug my shore power cord into the generator. It’s not an on board unit either.

- I have a neutral bonding plug for use with my Honda 2200/2000 for use with the EMS and also have a bypass switch for it if needed.

So what do you want to accomplish with the EMS? Sounds like overkill given the above.

 

[Henry J Fate]

What makes this a little complicated is that he has an inverter and a converter.

If you were to use an inverter charger and remove the converter from the design, you would have the extra switch needed to make this very simple. The added switch would be built into the inverter charger.

I would consider revising your plan to an inverter charger however, there will be some additional costs involved but a much better and safer system will result.

 

[Hewster]

So what do you want to accomplish with the EMS? Sounds like overkill given the above.

EMS is only to protect from campground power for the most part.

And long story short I have a Honda 2200 and 2000. Honda says they can be paralleled together if within a certain serial range. Mine are not within that range.

So “a low voltage condition may occur” I’m also trying to find the truth, situations and such behind this, which is why I want to run it with the EMS.

I’ve not been able to encounter a low voltage situation in any testing I’ve done

 

[JayArr]

much better and safer system will result.

I don't know where you get that conclusion Henry. If he was starting from scratch I'd agree, buy a combination inverter/charger so you don't need a separate switch but he alrealy owns 95% of what he wants and adding a transfer switch completes it.

The combination inverter charger is not better or safer.

 

[Hewster]

What makes this a little complicated is that he has an inverter and a converter.

If you were to use an inverter charger and remove the converter from the design, you would have the extra switch needed to make this very simple. The added switch would be built into the inverter charger.

I would consider revising your plan to an inverter charger however, there will be some additional costs involved but a much better and safer system will result.

Yah I’m very aware of the inverter/charges but was wanting to make the parts I have work for what I need currently.

May just end up going with a inverter/charger unit in the future to simplify even more, as well as better battery charging features especially if I upgrade more than just the dual 6v batteries.

 

[JayArr]

Hewster - what converter do you have?

Have you considered adding a long line to your converter and plugging it separately into one of the gennys and running the rest of the trailer on the other?

When at a powered campsite you could plug the trailer into the 30A outlet and the converter into the 20A outlet.

 

[Lou Schneider]

EMS is only to protect from campground power for the most part.

And long story short I have a Honda 2200 and 2000. Honda says they can be paralleled together if within a certain serial range. Mine are not within that range.

So “a low voltage condition may occur” I’m also trying to find the truth, situations and such behind this, which is why I want to run it with the EMS.

I’ve not been able to encounter a low voltage situation in any testing I’ve done

It's unlikely a Honda EU2000 or 2200 will brown out. Usually they produce full voltage until their maximum power is exceeded, then they just shut down. "A low voltage situation may occur" sounds like corporate CYA.

I'd try paralleling them. You won't hurt anything, it's just that one may shoulder more load than the other and overload before you reach the full combined power.

 

[Hewster]

Hewster - what converter do you have?

Have you considered adding a long line to your converter and plugging it separately into one of the gennys and running the rest of the trailer on the other?

When at a powered campsite you could plug the trailer into the 30A outlet and the converter into the 20A outlet.

I have the factory converter/charger. WFCO I think is the power unit.

I have not considered that, as most of our camping is boondocking.

 

[SuwanneeDave]

Y

Anyone else done this? Tips? Ideas?

Yes that is what I did. My transfer switch even had a wiring diagram showing how to hook up so the converter is activated when plugged in to shore power. If you are going to be using an inverter type generator you will need a way to bond the neutral and ground coming from the generator or the EMS will see an open ground and not allow power.

 

[Hewster]

It's unlikely a Honda EU2000 or 2200 will brown out. Usually they produce full voltage until their maximum power is exceeded, then they just shut down. "A low voltage situation may occur" sounds like corporate CYA.

I agree it’s just a CYA thing. They’ve paralleled together just fine in every test I’ve done. Frequency, voltage stays no steady. Everything has tested out perfectly

 

[Hewster]

Yes that is what I did. My transfer switch even had a wiring diagram showing how to hook up so the converter is activated when plugged in to shore power. If you are going to be using an inverter type generator you will need a way to bond the neutral and ground coming from the generator or the EMS will see an open ground and not allow power.

Which transfer switch did you use?