What an EMS has protected us from...

[RVhiker]

Shortly after we bought our new 2011 Jayco fifth wheel, I installed a Progressive Dynamics Electrical Management System (EMS-HW30C). It protects against problems that the incoming 120 volt power from the power pedestal (shore power) may have and cuts off the power before those problems can cause problems for you.

1) Reverse polarity (hot and neutral reversed)
2) Open ground - (no ground connection)
3) High voltage - over 132 volts
4) Low voltage - under 104 volts
5) High frequency
6) Low frequency
7) Replace surge protection

And in addition it has a timer. When the power is off and then comes back on, it will not be made available to the trailer for 136 seconds (which time must be set by the user). This protects your AC compressor from trying to start too soon, before pressures in the system are acceptable for starting.

All of these are detrimental in some way to trailer systems. Items 1) and 2) are especially dangerous to the health and continued life of the users of the trailer. Items 3) and 4) are dangerous to your trailer electrical components. Items 5) and 6), I got no clue. Item 7) means the surge protection device of the EMS is no longer working and needs replacement.

Since we installed the EMS, it has protected us from 1), 2) and 4). Tonight, during a thunderstorm, it protected us from 3). The highest voltage I saw - which the EMS had cut off to the trailer supply - was 142 volts. Yikes!

If you have an EMS, you know how important it is. If you don't have an EMS, think about getting one.

Sorry for the long post, but I am a believer in such EMS systems, especially now that mine has protected us from each of the first four problems. And protected our AC compressor from short cycling on many occassions.

[Fairenatic]

Originally Posted by RVhiker

...................................
Since we installed the EMS, it has protected us from 1), 2) and 4). Tonight, during a thunderstorm, it protected us from 3). The highest voltage I saw - which the EMS had cut off to the trailer supply - was 142 volts. Yikes!

If you have an EMS, you know how important it is. If you don't have an EMS, think about getting one.

Sorry for the long post, but I am a believer in such EMS systems, especially now that mine has protected us from each of the first four problems. And protected our AC compressor from short cycling on many occassions.

Yep. Just ordered my EMS HW50C today for my new TT!!!!

And with a lifetime warranty and modular design, should do its job for the life of the TT.

Thanks for posting. Nothing like real life experiences to bring home the point.

[SmokerBill]

Originally Posted by RVhiker

snip...
5) High frequency
6) Low frequency
snip...
Items 5) and 6), I got no clue.

Most electrical and electronic devices in the US are designed to operate on 60Hz AC. A higher or lower frequency could possibly cause damage.

[RedHorse1]

I'm on my 2nd Progressive EMS. The first was a pole-mount 30A and I installed the 50A in the 5th. Some stuff I buy on price and others on quality. This is the latter for me.
Their customer support is also excellent.

[jloco]

A progressive 30a EMS is one of the top items on my 'to do' list before hooking up the trailer at the seasonal site. Who's got the best price on them? I saw buy just a quick search on the web, you can save a few bucks depending where you buy it.

It looks like tweety's wants $249 not sure about shipping.
$239 at dyers with $10 coupon code. Free shipping.
Amazon is $230 + free shipping.
CW wants $304 not sure about shipping

Does anyone know of any other deals out there?

[clubhouse]

Originally Posted by jloco

A progressive 30a EMS is one of the top items on my 'to do' list before hooking up the trailer at the seasonal site. Who's got the best price on them? I saw buy just a quick search on the web, you can save a few bucks depending where you buy it.

It looks like tweety's wants $249 not sure about shipping.
$239 at dyers with $10 coupon code. Free shipping.
Amazon is $230 + free shipping.
CW wants $304 not sure about shipping

Does anyone know of any other deals out there?

Amazon's price floats dynamically, I picked up my 30a external pole mount EMS for $219 with free shipping a couple years ago. I have see. The price at that level since, so unless you need for an immediate trip just keep watching it and when the price is down pick it up.

[Camping Couple]

I picked up the progressive hard wired version from Amazon for $225 last year.

[jloco]

Originally Posted by Camping Couple

I picked up the progressive hard wired version from Amazon for $225 last year.

I see they have that HW version still for about the same. $223