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Acceptable power(volts) at the Pedestal
Hello All,
What is the acceptable power at the pedestal?
At Pelican Lake(Naples) I noticed that my inverters are reading between 127V – 131V close to coach shut down at 132V…
In November when we took the coach down, we had FPL(Florida Power) over to check pedestal power, was reading constant 124.5 on both legs. Tech mentioned that there they like to “run it” at approx 7.5% over the limit! Not sure what that means and why?
For example when plugged at Prevost in Orlando inverters are reading 118V – 119V, at Marathon in San Antonio 122V – 123V, at Hearthside in Petoskey 123V – 125V, running the generator(awhile ago) reading was 118 – 119V.
Most of the electrical components are referred to as 120V, but rated for 110 – 125V?
Not sure if this over voltage is related, but earlier this year one of the transfer switch connections(wire) was burned which took the entire coach down resulting in total “melt down” of the fridge…and some other issues…
Will this voltage have an impact on the Cruisair / compressor functionality?
Had Daniel the A/C tech check to voltage coming at one of the A/C units, 124.5V…
Marathon tech Terry suggested that 132v is max the coach can take, try to run the generator and compare values at the inverters, again…
Your comments/advise is appreciated!
Thank you!
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9 Replies
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Do you have one of these?
High/Low Voltage Protection:
Whenever A/C power falls below 104 volts, or rises above 132 volts, the EMS automatically shuts down power to the RV. The EMS will monitor the power and once the AC power rises above 104 volts, or below the 132 volt level, the time delay indicator flashes for the present time and then automatically restores power to the RV.I don’t know why or how the 132 volt limit was established. Maybe one of the smarter guys have some insight.
I use the EMS-PT50X ever time I plug in, even at home. I don’t recall an over limit shut down. But we’ve experienced low limit interruption a few times at campgrounds; typically older campgrounds that had 50amp added long after original build out.
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Hello Dick,
Thanks for your input, yes I use Progressive industries SSP-50XL at all times when plugging in. It just does not have the read out display, rest I believe is the same.
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Over the now 33 years of ownership we have plugged into power as low as 105, and as high as 128. Both extremes get my attention.
On the low side devices like the A/C units just shut down. At the high side, as long as it is below 130 I am OK, but vigilant above 125.
High voltages are rare and any steady 125 especially in the hot days of summer are a joy because amperage is down and the A/Cs love the higher voltage.
120 is a nominal voltage, just like 12 and 24. all are typically higher.
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Thank you Jon!
So 124.5V at the pedestal should be OK since south Florida is hot and the need/demand for A/C is obvious.
Then what would cause my inverters to display 126-130V if the input is 124.5V, just trying to understand?
I do have the Progressive Surge plugged in, there is no indication of any malfunction.
I am monitoring the readings from Michigan, looking at the variation, it make me uneasy…for example, I left 2 A/C’s ON with thermostat set to 80F, at 6:37AM – cooler temp outside, I assume the AC was not running – reading was 126V, at 11:00AM – at 78F outside, for sure A/C’s are running – reading is 129-131V.
Can the Power Co adjust the voltage down?
Is it possible the inverters are displaying erroneous voltage?
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I do not know enough about inverters, and yours in particular to suggest reasons for high voltage other than to suggest at low or no load their output power may be a little high, but will go to a more reasonable voltage as loads are added.
Is this higher inverter voltage something new?
Just to help you understand, when you are connected to shore power or the generator is running the inverters only pass that power through to the electrical panel and the devices themselves. That means the coach equipment is only seeing shore or generator power voltage.
When there is no shore or generator power then and only then are the inverters providing power to the electric panel and then to the devices. You have to be sure you know what your readings apply to.
Vantare coaches among some others all run on inverter power only and the shore power is for charging batteries.
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Some inverters like Victron can load share. That means the inverter can boost coach power from battery if demand is exceeding what the pedestal can provide.
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I like the digital readout on the EMS-PT50X. Tells me what the voltage is at the pedestal which often doesn’t match what I see on the inverter display.
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Thanks all for you replies…all good stuff…
We arrived at Pelican late Thursday/early Friday “readings” were same 129/130 on inverter 1 and 125/126 on inverter 2.
Next morning, turned A/C ON/OFF to see the difference, 2/3 V change on inverter nr. 1.
Unplugged shore power and started the gen, power 119/121 on inverter 1 with A/C ON, and steady 119 on inverter nr 2.
Plugged back into shore power…129/130 again…at this point I called Marathon support, talked to Dave. Explained the issue, he sent me right to the control panel to look at the readings…now…there is a difference on what reading you are looking at.
Jon touched briefly on that, but since I am not dealing on permanent basis with this…I was looking at the Inverter power provided by the inverters to the coach…WRONG…to verify the inverter incoming power, need to look at the AC1 for shore power and AC2 for generator power, I knew this but for some reason I was looking(stuck..) at the inverter power.
So now, the AC1 read was 124/124.5V on both inverters – as provided at the pedestal – pass thru.
If I turned the AC ON – looking at the inverter power readings – went up to 127/130 again, but that was ok per Dave.
Inverter 1 is the primary and provides power to charge the batteries and also power to (2) AC/fridge, etc at 50ams which explains the 127/130 as being OK.
When running the generator – it can run everything simultaneously in the coach, having 80amps capability if needed for all – that explains the 119/121V reading.
Then Dave suggested looking at the breaker panels (2) to understand what each inverter is controlling/supplying power to.
Lessons learned…
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132V is 120V plus 10%, just as 108 is -10%. That seems to me to be just a basic rule of thumb, not something specific to each load in the coach and what it can handle. I don’t like to let it go that far from nominal personally. I’d rather burn a couple gallons of fuel (if possible) than risk burning up something.
We have a friend with a track at the “end of the line” and the power company has struggled with getting him consistent voltage. With little load, the voltage can climb towards 130. With the track lights on and/or a bunch of guys running A/C, it draws it down. The power company can adjust it, I guess at the transformers.
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