Military generator testing load bank

[J Tiers]

We have an ex-military generator testing load bank, type A/M24T-8

This was apparently for testing the 28VDC and 120/240VAC output from the generators on KC-135 tankers (also Boeing 707).

The tie-in here is that we are trying to use it to test engine-generator sets, as a "dummy load". It will handle more than 150 kW, so that is OK.

The problem is that we don't have a diagram of it. (Them, actually, we have a 'good" one and a parts unit. ) The diagram on the inside of the doors has seen too much salt air, and is corroded past readable.

And, there seems to be a problem, since some combinations of KW loads and VAR loads act like they are shorted. Sort-of......

Does anyone know where such a thing as a manual or schematic could be found?

We tried the manufacturer. The buyer of the assets of that company says they have all the old stuff in boxes "downstairs", and have no particular interest in any investigating.

it's not like we have a lot invested in these, but we'd sure like to use them/it.

[Steve Dawkins]

I don't know what a KC-135 tanker is, but the ac generator on a Boeing 707 is probably rated at 400 hz instead of 60 hz. If your load bank is a resistive type, the heater elements aren't frequency sensitive. The controls and the fan motor(s) may be rated at 400 hz and therefore would be frequency sensitive. Running them on a 60 hz generator could cause problems.

Can't help you with schematics........Sorry.

[Wayne 440]

FWIW, a reactive load designed for 400hz would probably be for all practical purposes a short at 60hz.

[Wayne 440]

A brief google search revealed that this unit is apparently capable of DC, 400 and 60hz operation. It is the 4th listing on this page.

http://www.warbirdrelics.com/ground_support_equip_.htm

[J Tiers]

That is correct.

The inductors are all tapped with a 400Hz tap and the 60Hz value across the whole winding. It can provide a 0.8 power factor, all lagging, no capability for leading current.

I found that unit for sale, and also some others, but came up empty on the manual or diagram.

In the way of all such diagrams, each wire is drawn as entering a bundle, and numbered as it enters. You need to find the other end, but it is illegible in this case.