Burying a generator vault into a bank

[Sodo]

I'm gonna start with a manual form of overtemp shutdown. If it runs hotter than I like, I'll shut it down and redesign the ventilation. If it operates near enough to the limit, where an overtemp safety is necessary, thats too close for comfort, I'd rather oversize the ventilation. The" heat" is "16 Horsepower". Can 435 CFM blow away the heat that results from the generation of 16 HP? That is the "fan sizing question" and someone somewhere knows that answer. If I don't run across that person I'll have to find it by trial & error. My mini-excavator has 17 HP, that gives an idea of radiator size & fan size.

Remote start is whats on my mind currently.

Wonder if I should roll up carpet and put it inside the duct? Once I get it up & running I'll know about the sound level too.

Wet dirt, easy diggin!

Gonna bury the conduit. Have 240v, 120v, 12vDC, and signal wires. But my PVC cement is all dried up dangit I'm dead in the water.

 

[Industrial Toys]

I'm guessing, by code, you can't mix 110/220 and LV in the same conduit. Or?

We have some off-gridders a few miles away. Every cloudy day, the noise of that stupid (screaming) generator drives me nuts. Wish someone would bury it too!

 

[dragoneggs]

I wouldn't put anything inside the duct! Potential for fire, critters tearing into it and clogging, etc. Insulation should be on the outside IMO.

 

[prichard]

I'm guessing, by code, you can't mix 110/220 and LV in the same conduit. Or?

We have some off-gridders a few miles away. Every cloudy day, the noise of that stupid (screaming) generator drives me nuts. Wish someone would bury it too!

High and low voltage can be in same conduit as long as the insulation on all wires is rated for the highest voltage present.

 

[Industrial Toys]

I wonder if that applies to the Canadian Code. I always thought it was a no-no under any circumstances here. In the NEC, does that apply to conduit as well as enclosures?

 

[prichard]

Couldn't tell you about Canadian. In an enclosure you have to consider the devices as well. It is not uncommon to see separate conduit or separators in the boxes because some low voltage cable is not available with hive voltage insulation. You can get things like Cat5 cable in 300V insulation but it'll cost you. The other thing to consider is what type of signals because 120/240VAC can create too much noise for audio, video or communications to run together.

My background is industrial and commercial installations where we would never mix the 2 but that's as much practice as code.

 

[Redlands Okie]

I have been told by electricians to try to keep any data, phone type wires at least 12 inches from hi voltage wires when running parallel in a trench. I am not a electrician, just repeating what i was told to do when working on my place.

 

[prichard]

Yes that is preferred for noise isolation.

 

[PILOON]

Very often wiring inside of conduits is 220, which in fact is 2 x 110 so no problem there.
As to low voltage especially phone and or data, yes you want separation or at least good shielding otherwise you'll have 60 cycle hum (emi/rfi) interference. That will occur by inductance.

 

[jenkinsph]

Gasoline has about 120,000 btu/gallon (ballpark) a rough average is 70-75% is converted to heat and 25-30% is turned into flywheel power. So 120,000x.75=90,000 btus /gallon of fuel would be a good number. If your generator is using 1 gallon/hour you will be generating about 90,000 btu of heat. I recommend minimum of a 12" round duct since the paths are short with out much friction loss. On a 90,000 btu furnace I would use a 14" duct and expect a blower around 1250 to 1750 cfm.

What is the fuel burn/hr? If you use a half gallon per hour then expect to deal with half as much heat, about 45,000 btuh.

In the winter with sub freezing temperatures the fan could cycle to keep the engine warmed up. Assuming maintaining a 90F air temperature. In the heat of summer it may run non stop and it needs to be a large enough blower to keep up. A variable speed blower would be great, match the speed to the heat load.

If it were me I would plan for hot summer afternoon while running under maximum genset load.