Transfer Switch and EMS

overeasy · 03-03-2018, 12:27 AM

EDIT by site team: The following posts have been split off to their own thread

Can a transfer switch and ems be installed in this order, from shore power to transfer switch along with generator power to same transfer switch-power out from transfer switch to ems then power out from ems to rv ?

NO3putt · 03-03-2018, 01:31 AM

Look up on line for the installation instructions for what you plan on buying. As far as I know you can not have multiple inputs to the EMS. Skip

ScottBrownstein · 03-03-2018, 05:33 AM

Quote:

Originally Posted by overeasy

Can a transfer switch and ems be installed in this order, from shore power to transfer switch along with generator power to same transfer switch-power out from transfer switch to ems then power out from ems to rv ?

I don't see why not. I would bet that they don't talk about installing EMS units that way since it means you would have to break in after the transfer switch, which is normally not that exposed on a coach. Besides, generators seldom are the cause of the kind of problem that EMS units protect from.

On the other hand, a generator is not always the most perfect waveform. Sure it close to a sine wave but a lot more dirty than a power line feed. Some might bother an EMS.

CHICKDOE · 03-03-2018, 07:22 AM

yes, they can go either before or behind the transfer switch. advantages / disadvantages are:

before: protects transfer switch from bad shore power
failure of ems still allows generator power to reach transfer switch
after: protects for faulty generator power
failure of ems keeps all power from reaching rv

a previous post mentioned installation ease before or after transfer switch. this is a good point!

W5CI · 03-03-2018, 07:47 AM

The OP asked about a Transfer Switch, an EMS is a totally different animal. He must have a Generator if he has a Transfer Switch.

cavie · 03-03-2018, 09:57 AM

Quote:

Originally Posted by W5CI

The OP asked about a Transfer Switch, an EMS is a totally different animal. He must have a Generator if he has a Transfer Switch.

Op asked about a surge protector. Poster #9 asked about an EMS.

**wmtire** · 03-03-2018, 11:04 AM

Quote:

Originally Posted by cavie

Op asked about a surge protector. Poster #9 asked about an EMS.

Correct. The OP in 2016 asked about surge protection. The recent post #9 has revived a dormant thread, and the site team is going to split it off into it's own separate thread so as to not confuse the issues/questions.

conceptumator · 03-03-2018, 05:58 PM

Guess just depends on the EMS, but mine specifically stated it would NOT work with power feed from the generator to the EMS. It’s to be installed between the shore power feed and the ATS. Besides, why would you need to protect yourself from the generator power? You know it’s wired correctly.

overeasy · 03-03-2018, 07:01 PM

I do not have a transfer switch or ems at this time, the reason I asked about installing that way was I read that generators could damage my rv like shore power would. please let me hear your ideas for the best way. I have access to a Progressive PD52DCSV ts and a HW50C ems. I would like to keep the receptacle from generator so if needed could use gen to supply house during power outages. THANKS

CHICKDOE · 03-03-2018, 07:04 PM

the only reason (other than installation access) that I can think of where an ems would not work from a generator power supply is the lack of neutral ground bonding. there have been many posts about needed to install an 'Edison plug' on the generator to provide this bonding. but if we're talking about an internal transfer switch that highly suggests an internal generator that would already have addressed the bonding issue. we have a progressive industries hardwired 50 amp model and the installation manual has instruction for installing either before or after the transfer switch. other models of course may be different.

overeasy · 03-03-2018, 07:31 PM

The mounting location would be in the compartment with the shore cable and generator plug. not real big put I can put my forearm in almost sideways so not to bad. I will have to look up that EDISON thing. The generator is a 5500 cummins in my motorhome now.

CHICKDOE · 03-03-2018, 08:02 PM

you will not need any 'Edison plug' with the onan 5500 as it already has the bonding in the generator. the biggest issue you will have is access. and you will need some additional cable. get the proper size. if you are going to install it after the transfer switch look at the existing output cable from the transfer switch to determine if it long enough to be rerouted to where you are going to install the ems. or, look at where that cable terminates at you 110 volt distribution panel. you may have better luck mounting the ems near the distribution panel.

RamblerGuy · 03-04-2018, 05:59 AM

I installed the EMS after the transfer switch so the generator output would go through the EMS. As previously stated, the likelihood is low of having a problem with the generator. However, I found that the EMS will sense overload and shut off the power quicker than either the coach's main circuit breaker or the breaker on the generator.

Also, as previously stated, in this location the EMS does not protect the transfer switch from voltage spikes or high voltage. It still senses and protects from overload, frequency and ground/neutral problems.

overeasy · 03-04-2018, 09:23 AM

Does a surge protected transfer switch such as HW50C protect input before or a output after?

Gumpster808 · 03-04-2018, 09:29 AM

Quote:

Originally Posted by overeasy

Does a surge protected transfer switch such as HW50C protect input before or a output after?

We have the progressive 30 amp. Last season I plugged in an electrical strip to the outlet on the outside of the rv. The ems immediately cut power to the whole rv.

Had an error message that we had an open ground.

So even on the rv side of power it still protected things.

Threw that power strip away and bought a better one-all good after that.

Based on that it watches everything up and down stream.

Had been using that same power strip in the sticks and bricks for quite a while too.

overeasy · 03-07-2018, 02:15 PM

I spoke with the manufacturer of both items. Progressive dynamics told me if I install their PD52DCSV surge protected transfer switch I would not need the ems device becauoryse the ats will do the same things. Any thoughts on this theory?

CHICKDOE · 03-08-2018, 08:02 AM

i looked at the progressive dynamics transfer switch. I have a hardwired progressive industries ems. some thoughts:

the surge protected ats is probably less expensive than a separate ats and ems.
the surge protected ats is probably easier to install than a separate ats and ems.
it appears the progressive industries ems provides some functions the surge protected ats does not. among them:
- high / low voltage disconnection
- time delay to allow for a/c bleed down
- manual bypass
but the one thing that seems to be a glaring difference is the lack of a display on the surge protected ats. the ems has a display unit that shows voltage and amperage on each leg as well as any error condition is has sensed. I refer to the voltage and amperage data occasionally.

but each person's needs and objectives are different. you asked for thoughts. these are just thoughts.

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