Community Forums

RV Vagabond · 08-08-2022, 08:42 PM

How low of a voltage is it safe to use?

I am thinking around: 85 or 90 or 95 or 100

MrMark52 · 08-08-2022, 08:55 PM

For any equipment, the standard is +/-10%.

Resistive devices (like tungsten light bulbs), it really doesn’t matter.

For indicative devices, like AC fan motors and A/C compressors - + is better than - but neither are good operating conditions.

96 Wideglide · 08-08-2022, 08:55 PM

Believe my PI surge protector shuts down power to the coach at 103V.

TB673 · 08-08-2022, 09:00 PM

I believe that the general rule thumb is + or - 10% of the Utility's generated voltage which in most instances is 120 VAC.
That puts the low voltage at 108 VAC and the high voltage at 132 VAC.
My Progressive EMS will open circuit at 104 VAC to prevent any damage to equipment.

Tim

code2e · 08-08-2022, 09:16 PM

Since you have a variety of electrical and electronic components in a modern RV. You need to allow for the weakest link to protect everything.

Think the number you should go by is 108 VAC. Below that, something could be damaged. Seems like it's always the spendy stuff that gets hurt first.

**NLOVNIT** · 08-08-2022, 10:18 PM

My PI is set to shut down my power at 105V for the low. I would NOT go below that as damage to systems/appliances will surely happen if below that for any length of time.

Persistent · 08-09-2022, 08:01 AM

My roof air conditioner manual says 108 volts is required. If the voltage was being measured at the pedestal, I would require 110 volts minimum to allow for future fluctuations and line loss between pedestal and roof A/C.

2cyber71 · 08-09-2022, 08:05 AM

Anything below 108 volts will damage your AC
It’s the first thing to die.
My AutoGen default setting kicks in at 108.
I am unable to change it so, most RV manufacturers probably would tell you 108 is a minimum.
At 80 volts you will be running things pretty hot and melt control boards and more

glwinger · 08-09-2022, 08:20 AM

You have to measure the voltage while the AC or microwave is running. 108 static voltage is not a good measurement. That voltage will drop as soon as you put a load on it.

mistercee · 08-09-2022, 08:26 AM

Quote:

Originally Posted by 2cyber71

Anything below 108 volts will damage your AC
It’s the first thing to die.

So is it safe to say that as long as your feeding 108v or more to the A/C, you can run it without concern?

I'm asking as I've seen it posted here and other forums that you should never run the rooftop A/C on a standard 15/20 amp house outlet. When getting our TT ready for a trip here at home I routinely run one A/C while connected to a dedicated 20a circuit in my garage. I have about a 60' run to get to the outlet and connect using one 50amp RV extension and one 30amp RV extension, stepping down with dogbones.

The plug in voltage display in the trailer never indicates lower than 113v and typically sits at 117v.

So, safe to do?

Argosy · 08-09-2022, 08:52 AM

Quote:

Originally Posted by glwinger

You have to measure the voltage while the AC or microwave is running. 108 static voltage is not a good measurement. That voltage will drop as soon as you put a load on it.

The voltage should bounce back even with a microwave or AC running. If it doesn't there's a problem with the wiring.

I'll agree 108v-132v is safe.

wolfe10 · 08-09-2022, 08:55 AM

Quote:

Originally Posted by Argosy

I'll agree 108v-132v is safe.

Good general rule.

Some equipment is less sensitive than that, but only stray from the above after confirmation in the equipment's owners manual.

Arch Hoagland · 08-09-2022, 09:23 AM

I use both of these meters and shut off my air conditioners when they are at 108 volts.

https://www.amazon.com/Voltage-Evers...s%2C147&sr=8-6

https://www.amazon.com/Prime-Product...s%2C147&sr=8-5

azpete · 08-09-2022, 09:48 AM

in my opinion, low voltage is responsible for a lot of fires and burned out appliances in rv’s. especially ac’s and refrigerators.
just my opinion. not based on any studies other than my own experience.