EMS 50 High Voltage Cutoff ???

**Coheeba** · 04-16-2019, 11:06 AM

I recently camped at FD Roosevelt State Park in Georgia and had my Progressive Industries EMS HW50C cutoff each night at around 10pm and then resume around 8am. The error was E5 and signifies high voltage. The reading indeed was high 133-134v on leg 2. Has anyone seen this and what are the potential issue with bypassing and running on the high voltage?

**Coheeba** · 04-17-2019, 12:58 PM

I have done some research and found that "residential voltages have changed over the years, 110/220 115/230 120/240. The power companies have increased the voltage to supply power to more customers without upgrading the whole grid. Most RV AC units state 115v i.e.

The unit is a 115VAC, 60Hz appliance. The proper operating
range is between 103 and 126.5 volts AC. The voltage
reading should be taken at the unit power supply leads.
One test should be performed when the unit is turned OFF
and another with it running under load. If the voltage is not
within the proper operating range, it must be corrected before
operation of the unit.

It is understood that a 10% over/ under is safe and the EMS systems assume that but, they assume 120v - 108v low 132v high cutoff; but the AC units state 115v you have a 103.5v low and 126.5v high.

**howson** · 04-17-2019, 01:42 PM

Originally Posted by Coheeba

I have done some research...

Just so you know--probably lots of us following this thread but there's no comments because none of us have an answer. If you talk with Progressive please post what they tell you.

-Howard

**Coheeba** · 04-17-2019, 02:12 PM

That's my next step

**boyscout** · 04-17-2019, 02:14 PM

@Coheeba, I'm one of the lurkers that @howson mentions. I've used the EMS HW50C for two winter seasons, maybe 40 different sites in the eastern half of the U.S., and not had your experience. Thanks for reporting whatever else you learn about this.

**gbkims** · 04-17-2019, 02:55 PM

Maybe because the air conditioners have motors, they're rated voltage is lower than other appliances/electronics.

Motors have nameplate ratings (115,208,230,460) that are lower than the nominal distribution voltage like 120,240,480.
National Electric Manufacturers Association (NEMA) sets the standards for electric motors and their nameplate ratings in the USA.

https://www.flowcontrolnetwork.com/h...d-longer-life/
Voltage & electric motor performance
"The lower voltage rating on the motor considers the voltage drop that occurs because of the impedance of the circuit connecting the transformer and the driven equipment.
...
The highs & lows of electric motor voltage
Motor damage can occur when the utilization voltage is significantly different than the voltage for which a device is rated. Overvoltage is a condition that, per the listed standards, begins with a voltage 10 percent above the rated motor voltage."

https://www.ecmweb.com/design/highs-...-motor-voltage
"High voltage on a motor tends to push the magnetic portion of the motor into saturation. This causes the motor to draw excessive current in an effort to magnetize the iron beyond the point where magnetizing is practical.

Motors will tolerate a certain change in voltage above the design voltage. However, extremes above the design voltage will cause the amperage to go up with a corresponding increase in heating and a shortening of motor life."

**Country Campers** · 04-17-2019, 05:43 PM

Gene

What the heck was all of that

, I am a dumb dumb with electricianese , could you put that in other terms , like you will be fine or not please.

Brian

By the way I always like your input even though I do not understand most of it.

**Papahoosh** · 04-17-2019, 06:23 PM

Originally Posted by Coheeba

I recently camped at FD Roosevelt State Park in Georgia and had my Progressive Industries EMS HW50C cutoff each night at around 10pm and then resume around 8am. The error was E5 and signifies high voltage. The reading indeed was high 133-134v on leg 2. Has anyone seen this and what are the potential issue with bypassing and running on the high voltage?

I am going there next month, should I be concern?

**howson** · 04-17-2019, 06:32 PM

Originally Posted by Country Campers

Gene

What the heck was all of that

, I am a dumb dumb with electricianese , could you put that in other terms , like you will be fine or not please.

Brian

By the way I always like your input even though I do not understand most of it.

Think of it this way, Brian. Normal voltage is like a cool misting spray. Ahhh, feels good, right? Overvoltage is like getting hit with a bucket of ice water. Now you're drenched and thinking, "WHAT THE....!!!!!!!!!!!!!!!!" Both scenarios involve the same substance (water) but they are not the same result.

How's that for simplifying?

**gbkims** · 04-17-2019, 06:45 PM

Originally Posted by Country Campers

Gene

What the heck was all of that

, I am a dumb dumb with electricianese , could you put that in other terms , like you will be fine or not please.

Brian

By the way I always like your input even though I do not understand most of it.

Sorry about that.

, it's the electrical geek coming out.

I wouldn't bypass the EMS in the under/over voltage conditions.
The air conditioners are affected more because of their motors.