Honda 3000is mystery solved!

[kstampa]

I thought this information would be very helpful to someone who may experience similar symptoms when using any generator. This problem baffled me for quite some time.

I own a Honda 3000is. I noticed the gen periodically tripped to overload when running my 13.5KW AC and othe small appliances. I believed that perhaps the gen was underpowered for my AS - see http://www.airforums.com/forums/f448...ccd-42102.html

Upon closer examination I discovered that one of the prongs on the 30 amp cord male end was a little loose and the rubber around it slightly melted. I cut the male end off and rewired it. All was well for a while.

Then while begnning our FL-Smoky Mtn trip, all ac power went out in the AS while connected to park power. The other end of my 30 amp cord that attaches to the trailer had shorted and fused (metal to metal) to the AS receptacle. I had to use a sawzall to cut the back half of my cord off so I could remove the fused pieces from the AS receptacle. I replaced the cord end with a new female end and all has been great! NO MORE ELEC ISSUES WHEN RUNNING MY 3000IS!

In summary, be very careful of worn electrical cord ends when connecting to generators. Gen may run and power your AS but not deliver the fullest potential! Thanks and good luck!

[Crusty]

That's a known effect with generators. Most reactive electrical loads (such as ac motors) require a certain amount of power to operate, and if starved for voltage (such as by an underperforming generator) they will attempt to compensate by accepting more current to meet that power requirement. This increased current in all the wires powering the motor causes increased heating in those wires and can lead to melted insulation and even conductor fusing (melting). High resistance electrical connections also cause local heating of the conductors.

[kstampa]

Crusty, the gen is brand new, the AS is 2004. I thought it was a cord or plug end failure. My point was "keep an eye on cord condition and specifically the end of the cords". You think it's a gen issue?

[Crusty]

Nope, I do believe that it was a cord issue now.

Initially I did think it could be a generator issue, but since it's a new Honda that seems unlikely, and so my next guess in your case would be a high resistance connection which most likely occurred where the cord connects at the trailer receptacle. The damage could have begun some time ago too.

High resistance connections begin heating when even normal circuit current passes through them and that heat can melt insulation, make the connection resistance increase or even melt the wires. The high resistance can also starve a motor in the circuit for voltage, the motor will try to compensate by accepting more current and the increase in current across the high resistance point will cause it to heat even more.

What's especially insidious about these types of problems is that they don't always trip circuit breakers or open fuses because the circuit current remains below the trip point due to the high resistance in the circuit. Circuit breakers and fuses only protect you when there's too much current in a circuit. You can actually have a fire going on at a high resistance connection and it won't trip a breaker until the wires short together.

A friend of mine had this happen on his boat and the only thing that that prevented the fire was that the wire melted in two and current flow stopped, but you could tell that everything around that point was about to burst into flames. And the culprit - one of those damn push-on crimp connectors.

I would guess in your case that you had conductors that would short together when they got hot and that's what tripped your overload, until finally they fused together.

But undervoltage generators can damage electrical circuit components because of the increased currents from motor compensation. This is what burns out a/c compressors when they're starved for voltage but it can also result in heating and high resistance in connectors.

[b8sfamily]

Originally Posted by Crusty

Nope, I do believe that it was a cord issue now.

Initially I did think it could be a generator issue, but since it's a new Honda that seems unlikely, and so my next guess in your case would be a high resistance connection which most likely occurred where the cord connects at the trailer receptacle. The damage could have begun some time ago too.

High resistance connections begin heating when even normal circuit current passes through them and that heat can melt insulation, make the connection resistance increase or even melt the wires. The high resistance can also starve a motor in the circuit for voltage, the motor will try to compensate by accepting more current and the increase in current across the high resistance point will cause it to heat even more.

What's especially insidious about these types of problems is that they don't always trip circuit breakers or open fuses because the circuit current remains below the trip point due to the high resistance in the circuit. Circuit breakers and fuses only protect you when there's too much current in a circuit. You can actually have a fire going on at a high resistance connection and it won't trip a breaker until the wires short together.

A friend of mine had this happen on his boat and the only thing that that prevented the fire was that the wire melted in two and current flow stopped, but you could tell that everything around that point was about to burst into flames. And the culprit - one of those damn push-on crimp connectors.

I would guess in your case that you had conductors that would short together when they got hot and that's what tripped your overload, until finally they fused together.

But undervoltage generators can damage electrical circuit components because of the increased currents from motor compensation. This is what burns out a/c compressors when they're starved for voltage but it can also result in heating and high resistance in connectors.

Crusty, I just purchased my first AS. A 31' 1986 Sov. You see pretty knowledgeable about generators and power needs. I have been looking at a Honda 3000. But I notice that many people parallel 2 Honda 2000's. Can I get by with the 3000 or 1 2000??? running AC?

[Fyrzowt]

Two 2000's in parrallel, or one 3000.

[Crusty]

My approach to the problem would be to buy a generator(s) which can supply 30A continuous (the max power input for my AS) with a bit more headroom for insurance, so 30A x 120V = 3600W (continuous) would be my minimum. The advantage of two generators in parallel over a single generator is that they each weigh half (roughly) and are a lot easier to load/unload on an old abused aching back.

You do need to do an appraisal of your power needs and if you are certain that you can get by with a lower maximum power input then you can adjust your generator requirement for that figure.

Sit down with a paper and pencil and total up the wattage of all of the electrical appliances that you intend to use by looking at the rating tag on each, or if you have an electrician friend ask him to come over to have a few beers and bring his clamp-on ammeter and then you can spend some time turning stuff on to see what it draws exactly. Once you have this info you can make up a chart and see what can all be switched on at the same time and strategically control your power usage to stay within your generator's rating.

I should mention that there is a temporary startup current that is required to spin the compressor up in an air conditioner which can be 3 times the normal run current of the a/c. Your generator needs to be able to supply this startup current for a few seconds or your a/c will just sit there humming and burning up.

[Foiled Again]

Originally Posted by Fyrzowt

Two 2000's in parrallel, or one 3000.

Why are 2 2000's better than one 3000? WEIGHT. The 3000 weighs about 158 lbs. The 2000's each weigh 58 lbs. Most of us can wrestle 58 lbs on and off of our trucks or SUV's - It takes two big people to handle 158 lbs.

Of course you CAN run your generators from the back of a pickup truck, but if you need to leave the camp, it means disconnecting the power.

Also in cool weather, you only have to take one along.

Paula