We consider 'surge protection' to be much more marketing and nothing what RVers need. Campgrounds often have wiring problems that show up before we plug in or sometime after we are connected. To protect from transient or late-arrival problems, like when a few neighbors turn on their air conditioners, a device needs to have the ability to disconnect coach from shore power.
Progressive Industries EMS products have been a favorite, and something we have. These companies also make simple surge protectors that do not disconnect, some of their products may light a LED if something is wrong at that moment, but offer no other protection.
These devices that disconnect power look for under or over voltages and other anomalies, and sometimes they may turn things off because voltage is just at edge of ok / not-ok, like 130 volts or 109 volts. Voltage and measurements devices may not be consistent and even though device wants to disconnect, we may occasionally choose to keep the connection, like if we only have a few items running or if we will turn on roof air which will put an over volt situation back down to acceptable. This need to manually override is not often needed. But if we find our disconnect device has failed and thinks volts are bad, when with other meters we know they are ok, then the need to override is valid.
The reason for all the above manual override discussion, is Progressive Industries EMS hard-wired with remote meter has a manual bypass switch that will close relay no matter what the EMS thinks.
If we have any plug-in model, just removing it from outlet will keep electricity on.
I like the marketing info on the new, lower cost Hughes that have the EPO (emergency power off) feature, likely similar to Progressive Industries EMS. I have been in contact with Hughes General Manager who has not responded to my second inquiry as to the disconnect threshold voltages, so we have NO idea how their EPO models specifically work. We don't yet know how it is wired or how relay works. If we get our hands on one, will learn some of our answers. It would be nice for their web site to have specifications, installation instructions with photos of inside, and a wiring diagram.
If the Hughes EPO fails or we want to bypass it and keep RV powered, if we have the plug-in model, we just remove it from shore cable. BUT if we have the hard-wired model, it seems we are dead in the water as the Hughes EPO does NOT seem to have any way to bypass their relay.
Since we greatly prefer the hard wired devices and now have a PI-EMS hard wired before and after the transfer switch, each with separate remote readout with bypass switches, it is hard for us to desire the Hughes EPO unit. Wish we even knew the disconnect voltages.
When I called yesterday to see the difference in their two plug into pedestal models, (non EPO model and EPO model) she said from memory that she thought the shut off points were 104 and 133v. She asked me whether I wanted to check for the exact, for sure cutoff voltages and I said "no, that was close enough."
She also told me the EPO model was physically larger, had the bulldog logo on the front and that it lit up when plugged in. The EPO model is new for 2019.
She also told me they recommend plugging the Autoformer into the post ahead of their portable EPO model to avoid cutoff in the event of low voltage.
I now use my Autoformer between my rv inlet and the 50 amp power cord in my wet bay to call attention away from this unit. I check the pedestal first with a portable surge protector. Now, in my future, I see a low and high voltage disconnect a must. So...., I will be looking at all options with a Pacific Industries or Hughes unit.
Amazon.com: Power Watchdog 50 Amp Smart Bluetooth Surge Protector with Auto... (https://www.amazon.com/Power-Watchdog-Bluetooth-Protector-Shutoff/dp/B07PMJ2K95/ref=sr_1_8?keywords=Watchdog+hughes&qid=1552664708&s=gateway&sr=8-8)
Amazon.com: Progressive Industries EMSHW50C Surge Protector: Automotive (https://www.amazon.com/Progressive-Industries-EMSHW50C-Surge-Protector/dp/B007O6INSE/ref=sr_1_fkmr0_2?keywords=Presiccion+industries+ems&qid=1552919105&s=automotive&sr=1-2-fkmr0)
and the Hughes without the emergency power off:
Amazon.com: Hughes Autoformer PWD50 Power Watch Dog 50 AMP Surge Protector:... (https://www.amazon.com/Hughes-Autoformer-PWD50-Power-Protector/dp/B0791VGVZ1/ref=sr_1_1?crid=MAM3YAIOX38J&keywords=hughes+power+watchdog&qid=1552919210&s=automotive&sprefix=Hughes%2Cautomotive%2C284&sr=1-1-catcorr)
Barry (et. al.),
If you only had one device, where would you where would you install it?
A lot of our Foretravels have two transfer switches. Where would you install it in those coaches?
Thanks,
Trent
Trent, installing hardwired Progressive Industries EMS (or Hughes EPO) on cable from transfer switch to main panel 50-amp 240-volt breaker will protect from shore power and generator anomalies.
One way to wire the above is to remove just the 'transfer switch cable end', then connect it to EMS output terminals, and run a new cable from EMS input terminals to the transfer switch terminals where the cable was removed.
We do recommend finding a way to run a low-voltage cable from EMS location to easy to read, eyeball height, probably in kitchen area, where the small remote panel could be looked at when curiosity arises to know amps & volts on each shore cable leg. Wonderful when on 30-amp or lower-amp shore power.
EMS is also instant notification of our recent generator voltage regulators starting to fail. EMS will turn off power and the remote panel will show the high voltage on the display. No damage with full instant knowledge of cause.
Barry,
Thanks for the great information. I'm sure others will find it useful, too!
Trent
Very interesting. What about the Surgegard 50amp system:
Amazon.com: Surge Guard 34951 (50 AMP) - Full Protection Portable with LCD... (https://www.amazon.com/Surge-Guard-34951-AMP-Protection/dp/B07NW1Q52Z/ref=sr_1_fkmrnull_2?keywords=surgeguard+50+amp&qid=1552924005&s=hi&sr=1-2-fkmrnull)
It supposedly does the following:
1. Analyzes the pedestal to ensure proper electrical conditions before allowing power to the RV
2. Protection against open ground, open neutral, reverse polarity, miswired pedestal, low and high frequency, plus low and high voltage
3. Continued protection against low and high voltage and low and high frequency.
4. Only Electrical Protection System to offer load side protection against elevated ground line current and open neutral conditions (50A only) inside the RV
It looks like it analyzes the power source before connecting and it appears that it monitors the power source (#4 above), but is this enough?
Thanks in advance.
George, looks like your Surge-Guard will do all that Progressive Industries EMS portable does. For a portable unit, maybe the 'new' Hughes EPO may be the best value, with all the features and with Bluetooth and low price.