A few weeks ago our honda generator started killing my ac to dc chargers, it killed two fo them before we knew what was happening. My land lord says it is a over voltage surge. So I bought a surge protector. I did not realize that these cheaply made devices using Varistors would alow 330 volts through and wear out from build up charges.



And we could not figure out how to install it faster then my learning curve was going up. I finnaly found the right stuff on wikipedia, and aslo a PDF about “designing power surge rotectors”



Unfortunaly I do no thave any back ground in electronics, so I am hoping some one can tell me how to build a surge supressor device that will take thousands of small surges. I believe that it is only 240volts for some thing like a 30 to 60 seconds. I was able to hear a low rumble on my stero speakers comming from what I think was EFM coming off the chargers.



I believe that I can build a device from a shcematic if all the parts are specified. I have not finnished reading the PDF, but at first glance I did not see any specific details.

 

Surge suppressors are designed to limit short-term overvoltage spikes.
They cannot handle the power of an overvoltage for 30 seconds or more.
And it's likely not feasible to do that anyway, because it would consist of applying a short circuit to the generator to clip the peaks, which would generate high currents and power dissipation.

Sounds like you may have a faulty generator.

 

A few weeks ago our honda generator started killing my ac to dc chargers, it killed two fo them before we knew what was happening. My land lord says it is a over voltage surge. So I bought a surge protector. I did not realize that these cheaply made devices using Varistors would alow 330 volts through and wear out from build up charges.



And we could not figure out how to install it faster then my learning curve was going up. I finnaly found the right stuff on wikipedia, and aslo a PDF about “designing power surge rotectors”



Unfortunaly I do no thave any back ground in electronics, so I am hoping some one can tell me how to build a surge supressor device that will take thousands of small surges. I believe that it is only 240volts for some thing like a 30 to 60 seconds. I was able to hear a low rumble on my stero speakers comming from what I think was EFM coming off the chargers.



I believe that I can build a device from a shcematic if all the parts are specified. I have not finnished reading the PDF, but at first glance I did not see any specific details.

Have you thought of just buying one? Or better get your generator serviced by someone that DOES know what he/she is doing.

 

I think the Genset is hunting from time to time.
Could be a bad AVR

 

As above,

Surge protectors work by absorbing the over voltage and dissipating it as heat.

Each time they are 'hit' they de rate a little bit more,
they are designed as last line of defence, not constant use, some surge protector systems have lights that indicate the surge protector has been hit for this purpose.


So thats the problem, but not of much use to you,

solutions.

a) Get new generator / get generator serviced / fixed.

b) Over voltage trips. Do what they say on the tin. Like a circuit breaker, but designed for voltage. Voltage goes over trip level and they switch off. .. they do exist , but are a bit specialised suppliers, a quick google and I could not see any....

c) step down transformer. ... On basis that ac : dc converters are quiet tolerant on input voltages, a 240 volts in, 180 volts out transformer would limit the over voltage, and 'probably' still work the ac : dc converter.

d) UPS : These 'normally' have good over voltage capabilities having auto transformers

e) DIY , measure voltage and trip out if over volts. An op amp / comparator and relay should do, just remember mains can kill and I think its against forum rules to advise on mains powered stuff.

 

I forgot to say that my and lord wants to apply transformers to step up the voltage on his end and step down on my end. Because I am about 300 ft or a little more over in the forest. And becuse we are offgrid, with solar power. That is why we got this second hand generator. When the sun don't shine we have no electricity.



I suspect that the generator had problems from the last owner, and they though it better to pass it on to any one foolish enough. I was getting on my land lords case about building a generator out of a small car engine and DC motor. We had one goinng last year, but the gas tank of the car started leaking. So on goes the saga of learning to live off grid.



We had a large battery to explode also, so we are working on less than 11 volts. Most of my equipment is LED lights and a car stereo. And even my computer is buffered by the ac to dc transformer. Good thing, I would would have been floored by my $7oo doller computer burning out.



Today I just rigged a small computer fan to vent my battery compartment, becuse I was smelling hydrogen....and I thought it was from my little sewer bucket.



I will have to tell you what he says about the transformers he wants to install.

 

sounds fascinating,

Re Hydrogen, it has no smell to humans,
I guess its the battery acid fumes / by products you were smelling,
Hope the fan is blowing into the room,
not sucking hydrogen / air mixture through it..
natural ventilation, pipe to ceiling, pipe below batteries to out side,
hydrogen rises, clears room,


Get a better generator..

 

As above,

Surge protectors work by absorbing the over voltage and dissipating it as heat.

Each time they are 'hit' they de rate a little bit more,
they are designed as last line of defence, not constant use, some surge protector systems have lights that indicate the surge protector has been hit for this purpose.


So thats the problem, but not of much use to you,

solutions.

a) Get new generator / get generator serviced / fixed.

b) Over voltage trips. Do what they say on the tin. Like a circuit breaker, but designed for voltage. Voltage goes over trip level and they switch off. .. they do exist , but are a bit specialised suppliers, a quick google and I could not see any....

.

You could probably add a simple circuit to rig a standard ELCB. They work on the current going out and the current coming back being equal (ie; not going anywhere it shouldn't). detect over voltage and trigger injecting unbalanced current into the neutral return.

 

This sounds good, is that a kind of breaker? Show me link please....
do I need a circuit other than what is in the brakers?
Earth leakage circuit breaker?? ok I found a page to explane about these things....I gotta lot to learn.

You could probably add a simple circuit to rig a standard ELCB. They work on the current going out and the current coming back being equal (ie; not going anywhere it shouldn't). detect over voltage and trigger injecting unbalanced current into the neutral return.

 

This sounds good, is that a kind of breaker? Show me link please....
do I need a circuit other than what is in the brakers?
Earth leakage circuit breaker?? ok I found a page to explane about these things....I gotta lot to learn.

Read what I said - you need to add an overvoltage detector that triggers the unbalanced current.

In the UK; ELCBs are mandatory in the meter cupboard - there's lots of types from hundreds of suppliers.

 

it is blowing out? the only vent is on the side wall....maybe I have to open it up more.
I also smelled some kind metalic odor....possibly the mold under my bed?

sounds fascinating,

Re Hydrogen, it has no smell to humans,
I guess its the battery acid fumes / by products you were smelling,
Hope the fan is blowing into the room,
not sucking hydrogen / air mixture through it..
natural ventilation, pipe to ceiling, pipe below batteries to out side,
hydrogen rises, clears room,


Get a better generator..

 

“Outback transformer” is what we have, no electronics inside.

And would it be better to use a voltage regulator than the ground leakage breaker?

what kind? gotta picture/ link? 240v to 180v?

 

ok I have no idea what to look for.....all I see is over priced stuff. anyone got a nice circuit to build?
how about this?
APC LE1200 Line-R 1200VA Automatic Voltage Regulator

 

We are going to have to fix the generator. There is nothing else that will do.

So this is a realy good question form my land lord:


How to supress teh spike from the pressure switch that energizes the transformer in teh generator... the points turn on and off sharply, and then it relays the power throught he tarnsformer and sends out very high voltage, like more than 240...


Will a capacitor do the trick? What value?

 

The fan motor is brushless so I am hoping that magnetic feilds do not make hydrogen explode. It would be suicide to use a brushed motor in a battery compartment.

 

The fan motor is brushless so I am hoping that magnetic feilds do not make hydrogen explode. It would be suicide to use a brushed motor in a battery compartment.

The magnetic fields can not cause a fire.
A.H.W.