GENERATOR TEMPERATURE

[Kelvin12]

G'Day all,

One for the experts, What sort of maximum temperature would you expect/worry about in an enclosed sound proof generator box...... Not 100% sound proof of course, but fully lined with sound proofing and with forced intake and extraction fan, (bilge blowers). I was planing on adding a thermal cut out switch, don't know if they are adjustable as yet but recently say this on ebay. What does everyone think before I get carried away with this.

I know from a friend he was worried about the temperature with the genny running in a similar set up and thought it was way to high for comfort. Not sure what his fan set up was.

Dirk

[BruceS]

Dirk I haven't seen your setup......... is it an aircooled engine? I know some of the ex-charter buses have watercooled engines. Air-cooled would probably need not much more that 10-15 degrees above outside temperature otherwise it'd maybe shorten it's life.
Some decent gennies have temperature and low oil cutoff switches built into them.
What make/model is yours?

[T1 Terry]

I'm thinking 60 deg would just about pull it up, trying to cool the alternator and the engine with air much hotter than 60deg c would b difficult. Many of the Hondas have problems with fuel vapouring in the carby and fuel line with enclosed generator boxes so some way of cooling the air entering the box would be beneficial, fine mist water spray over a filter pad maybe, like the swappy coolers.

[Kelvin12]

Generator is an XG-SF 3600 (Chinese, Ebay) 3kw unit with a Honda motor. Seems like a good unit. Used it a couple of times playing around with it and it doesn't breath hard running anything to date, large angle grinder, large makita saw and a 12cfm compressor. Stays on the economy setting with no sign of struggling. At this stage I am going to run a 4", 235 cfm bilge blower for the inlet blower with a 3", 100 cfm extractor. If this is insufficient then I'll double up as necessary. Saw a similar set up on a diesel generator and it seemed to cope well enough.

Dirk

[BruceS]

Dirk a lot of heat gets radiated from the exhaust. Not out the end but out of sides of the muffler and pipe.
Of course Pro fishing boats have sea water cooled heat exchangers etc but thier motors are below deck in a confined space.
They wrap their exhast pipes in a very thick layer of what looks like asbestos 'rope' to lower noise and heat.
You may be able to create some ducting directly into the cooling air intake. (not air cleaner) A bit like some computers now suck air directly in from outside the box.

[Kelvin12]

That was my plan to direct fresh air directly into the intake vents at the front of the unit and extract hot air and exhaust from the other end, flow through effect. I can get this ducting right up to the vents at either end with ducting tubes. The generator only gets air into and out of the vents front and rear, the casing is enclosed top, bottom and sides with no venting.

There may be some internal fan but I can't see one just by looking into the casing. I haven't pulled it apart to have a look at this stage. When I tested it I had it running for a good hour on a hot day without any problems and it didn't get hot at all. I was quite surprised.

This is a similar genny, bigger than my 3kva model but identical in appearance by the same manufacturer.
http://www.ebay.com.au/itm/SILENT-5KVA- ... 43b863b068

Dirk

[BruceS]

It would be quite simple to have a cheap household fan on the inlet side running off the generated power while the genny is working. Obviously those generators, like most of them except the Cummins/Onan ones, are really designed to be out in an open area when running but as long as the hot/warm air is removed away from the unit it should be OK.
They should be designed to suck/push enough fresh air in to keep them going OK.

[Kelvin12]

Running AC fans is popular in the US m/h's. They seem to do that in preference to using bilge blowers. Really didn't consider the AC fans but if the blowers don't work then I'll look into the AC fans later. A friend has a similar set up using bilge blowers on a smaller Honda generator blowing air in via a shroud over the intake vents and similar on the exhaust end and it seemed to run quite well.

Dirk

[T1 Terry]

The alternator also needs cold air fed into it to stop it from overheating, probably better to pump the air into the box and shield the exhaust joined to a stainless pipe larger than the exhaust heading out of the box, that way the air is forced across the exhaust and carries the heat outside.
I looked at lots of ways of cooling and quietening a generator, including a water jacket box and radiators each end to supply cold air air in and take the heat out, water cooled engines and alternators, I gave up and changed battery types and invested in more solar and good inverters, far less hassles.

[Kelvin12]

G'Day Terry,

Hopefully the generator will get little to no use at all, that's why I went with the el-cheapo ebay version rather than a Honda /Yamaha gen. I regard this one as a throw away rather than a keeper. I'll only use this as a last resort, bad weather type situation. Hopefully the solar and batteries etc. will do the job without use of this generator at all. Well that's the plan but of course......

Dirk