Hi! I bought a 250 Watt Electric Heater to stave off the chill at night (the tag says it uses 2.1A). We have solar panels to charge our 200A battery (I don't think that matters, but just in case). Before the trip, I plugged the 250 Watt Heater into the 300 Watt inverter, and the inverter is plugged into the cigarette lighter in the camper. (The wire that runs from the cigarette lighter to the battery sized for 10A.) It worked fine. But now that my son and husband are on their trip, when they plug in the heater, the 10A fuse blows that is at the cigarette lighter. Twice.They are able to play a DVD and TV by plugging it into the inverter. So everything works for the DVD and TV.Nothing else is being charged or used on that inverter, nor at the cigarette lighter.Note: There is an electric fridge/cooler, and it's being powered by the same auxiliary battery, but it's not on the same fuse (if that makes sense; I know I am not using the correct terminology). My hubby just got to a campsite that has a power supply, and the heater works fine. So at least he is able to use it now without blowing fuses.Any suggestions as to where we can start looking for the issue(s)?TIA.

My first guess is the antenna amplifier is on. Many power outlets get their power from the same circuit the antenna amplifier is on. Turn the amplifier is off. Many have an LED to show if they are on or not.Otherwise, check to see what else is off when the fuse blows just to make sure something else like a fridge etc isn't drawing a bit of power from the same circuit. Also, it may make a difference at what the setting is on the heater for temperature. The difference in the surge could be different if you turn it all of the way down, turn it on, and then gradually turn the thermostat up.

jimh406 wrote:My first guess is the antenna amplifier is on. Many power outlets get their power from the same circuit the antenna amplifier is on. Turn the amplifier is off. Many have an LED to show if they are on or not.Otherwise, check to see what else is off when the fuse blows just to make sure something else like a fridge etc isn't drawing a bit of power from the same circuit. Also, it may make a difference at what the setting is on the heater for temperature. The difference in the surge could be different if you turn it all of the way down, turn it on, and then gradually turn the thermostat up.I don't think we have an antenna amplifier. I had to google it to see what it was. We only watch DVDs with our little TV. We will check the fridge, and I will ask my hubby about the circuits. I, too, thought of that first surge. I texted him to see if he started the heater at 250 watts or on the lower setting. I think when I tested it at home, I started it on LOW and then powered it higher after a few minutes. That just seems logical to me. Question: Because the inverter is only rated for 300 Watts, if the heater exceeded that 300 watts, would the fuse at the cigarette lighter blow, or would the inverter overheat? It seems that the 10A fuse should have been fine, even if there was a power surge because the surge likely couldn't have been more than 10A. But the bottleneck is at the inverter, so what happens when the inverter has to deal with more than 300 watts? A blown fuse (but I would think that the inverter would stop working)?The fuse blowing happened immediately. Turn on heater and fuse blown. No time for anything to overheat.HeaterInverter

maria_bettina wrote:Hi! I bought a 250 Watt Electric Heater to stave off the chill at night (the tag says it uses 2.1A). We have solar panels to charge our 200A battery (I don't think that matters, but just in case). Before the trip, I plugged the 250 Watt Heater into the 300 Watt inverter, and the inverter is plugged into the cigarette lighter in the camper. (The wire that runs from the cigarette lighter to the battery sized for 10A.) It worked fine. But now that my son and husband are on their trip, when they plug in the heater, the 10A fuse blows that is at the cigarette lighter. Twice.They are able to play a DVD and TV by plugging it into the inverter. So everything works for the DVD and TV.Nothing else is being charged or used on that inverter, nor at the cigarette lighter.Note: There is an electric fridge/cooler, and it's being powered by the same auxiliary battery, but it's not on the same fuse (if that makes sense; I know I am not using the correct terminology). My hubby just got to a campsite that has a power supply, and the heater works fine. So at least he is able to use it now without blowing fuses.Any suggestions as to where we can start looking for the issue(s)?TIA.No worries, a common misconception.Technical: P=I*E, 250W=2.1A*120VAC ok?The 'problem' here is to get 250W AC out of a inverter it may require 300W on the +12V side of things. (%80 efficient) which equates to: 300W/12V=25A - thereby blowing the 10A fuse on the cigarette lighter.So why did it work at home? (assuming at home you were plugged into shore power)With the additional current provided by the campers onboard converter charger the battery voltage would be higher than what it would be by itself.Consider if the battery voltage was 13.8V the current for 300W would be 21.7A and if the battery was @ 14.4V the current would be 20.8A.Since many converter chargers are designed to actually charge the onboard battery, I'd suspect your voltage while plugged in was ether 13.8V or 14.4V.- Mark0.

Mark- thanks for that explanation. I was wondering about the voltage early on, but couldn't get myself to believe the amps required for that small heater. When I tested the heater in the TC, if the TC was "plugged in" it would be a trickle charger to the aux battery (and honestly I can't remember if we were charging the battery or not). So if the issue that you described is the culprit, I suspect there is no way to use that 250 Watt heater in the TC. ????PS just talked to my hubby. The Renogy is reading 22V late in the day. So that's it. I tested the heater when the sun was up and the solar panels were charging the battery. The voltage was high, higher than it would be at night. Am I understanding that correctly?

I'm curious toi know what heater you are using. The link you provided directs me to the inverter.

Electrical Help pls | Good Sam Community

mbloof
Explorer
Jun 21, 2022
maria_bettina wrote:
Hi! I bought a 250 Watt Electric Heater to stave off the chill at night (the tag says it uses 2.1A). We have solar panels to charge our 200A battery (I don't think that matters, but just in case).

Before the trip, I plugged the 250 Watt Heater into the 300 Watt inverter, and the inverter is plugged into the cigarette lighter in the camper. (The wire that runs from the cigarette lighter to the battery sized for 10A.) It worked fine. But now that my son and husband are on their trip, when they plug in the heater, the 10A fuse blows that is at the cigarette lighter. Twice.

They are able to play a DVD and TV by plugging it into the inverter. So everything works for the DVD and TV.

Nothing else is being charged or used on that inverter, nor at the cigarette lighter.

Note: There is an electric fridge/cooler, and it's being powered by the same auxiliary battery, but it's not on the same fuse (if that makes sense; I know I am not using the correct terminology).

My hubby just got to a campsite that has a power supply, and the heater works fine. So at least he is able to use it now without blowing fuses.

Any suggestions as to where we can start looking for the issue(s)?

TIA.

No worries, a common misconception.

Technical: P=I*E, 250W=2.1A*120VAC ok?

The 'problem' here is to get 250W AC out of a inverter it may require 300W on the +12V side of things. (%80 efficient) which equates to: 300W/12V=25A - thereby blowing the 10A fuse on the cigarette lighter.

So why did it work at home? (assuming at home you were plugged into shore power)

With the additional current provided by the campers onboard converter charger the battery voltage would be higher than what it would be by itself.

Consider if the battery voltage was 13.8V the current for 300W would be 21.7A and if the battery was @ 14.4V the current would be 20.8A.

Since many converter chargers are designed to actually charge the onboard battery, I'd suspect your voltage while plugged in was ether 13.8V or 14.4V.

- Mark0.
maria_bettina
Explorer
Jun 21, 2022
jimh406 wrote:
My first guess is the antenna amplifier is on. Many power outlets get their power from the same circuit the antenna amplifier is on. Turn the amplifier is off. Many have an LED to show if they are on or not.

Otherwise, check to see what else is off when the fuse blows just to make sure something else like a fridge etc isn't drawing a bit of power from the same circuit.

Also, it may make a difference at what the setting is on the heater for temperature. The difference in the surge could be different if you turn it all of the way down, turn it on, and then gradually turn the thermostat up.

I don't think we have an antenna amplifier. I had to google it to see what it was. We only watch DVDs with our little TV.

We will check the fridge, and I will ask my hubby about the circuits.

I, too, thought of that first surge. I texted him to see if he started the heater at 250 watts or on the lower setting. I think when I tested it at home, I started it on LOW and then powered it higher after a few minutes. That just seems logical to me.

Question: Because the inverter is only rated for 300 Watts, if the heater exceeded that 300 watts, would the fuse at the cigarette lighter blow, or would the inverter overheat? It seems that the 10A fuse should have been fine, even if there was a power surge because the surge likely couldn't have been more than 10A. But the bottleneck is at the inverter, so what happens when the inverter has to deal with more than 300 watts? A blown fuse (but I would think that the inverter would stop working)?

The fuse blowing happened immediately. Turn on heater and fuse blown. No time for anything to overheat.

Heater
Inverter
jimh406
Explorer III
Jun 21, 2022
My first guess is the antenna amplifier is on. Many power outlets get their power from the same circuit the antenna amplifier is on. Turn the amplifier is off. Many have an LED to show if they are on or not.

Otherwise, check to see what else is off when the fuse blows just to make sure something else like a fridge etc isn't drawing a bit of power from the same circuit.

Also, it may make a difference at what the setting is on the heater for temperature. The difference in the surge could be different if you turn it all of the way down, turn it on, and then gradually turn the thermostat up.

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