Charging panels

[rob love]

Picked up a few of the charging panels shown in the photos below. What are they used on?

[Robert Bergeron]

No answer yet Rob ? What is the size of the unit please ?

[rob love]

5-1/4 x 6-1/2.

Still no idea what they were for. I picked up 3 from the local milsurp store.

[Jordan Baker]

Also would it be possible to get the distance between the mounting holes? How would the wires attach when connecting the feeds from the batteries and the generator?

Thanks

[rob love]

Holes are 5" apart.

The battery and generator hook up to the front of the panel on each of the knob type terminals.

The two banks would appear to be wired behind the panel No idea what the banks refer to......I would normally assume it referred to banks of batteries.

[David Dunlop]

That's an interesting puzzle, Rob. I too thought of banks of batteries when I first looked at it, but the front of the panel made no sense in that regard. These panels control generator and battery feeds to two separate banks of electronic equipment. It would not be logical to have the option of feeding a bank of batteries with another battery.

When you look at the back of the panels, there is an extra set of terminals, centre either side, the switches control electrical flow to, from either a gen source or battery source. These terminals match up with the ID labels of the front of the panel for the two 'banks', but the two banks would have to be connected from inside whatever cabinet this switch plate served as a cover for.

For large banks of electronics, needing 6 or 12 volts, I am thinking a large telephone relay setup. If these are military, possibly something used at a large HQ with a lot of incoming land lines. Not sure during the war, how much reliable commercial telephone system would be available for a large military installation so maybe the military had to bring their own.

David

[rob love]

Both switches are "on-off-on" type. As can be seen in the photo, the negative ground is live to both negative top posts, and the two left and right bottom posts of the banks.

The positives are both controlled by the switches. You can have the generator and batteries working together, or on opposite banks, or cut off altogether.

No part numbers that I can find. When I grabbed these, I thought they were army, but I suppose they could just as easily be airforce.

[Chris Suslowicz]

I think it's for two banks of batteries, but it's quite low power compared to the usual charging switchboard (unless those switches are bigger than they look).

It's the same function as the No.5 switchboard, and probably for the same reason: the equipment does not have any voltage control and would not enjoy being connected to a charging vehicle battery.

Battery banks connect behind the panel, generator and load to the terminals on the front. Top switch selects generator connection, Battery A, Off, Battery B, lower switch selects which battery is connected to the load. Check the switch details for the maximum current it can carry.

Chris.

[rob love]

Had a look at the switches and no amperage rating. However they were made by Carling, and have the part number ST40E. When I look up that part number, it gives a spec of 10 amps.

[David Dunlop]

It's probably a long shot, Rob, but does that switch show up in any military parts listings currently that might provide a clue as to what it was used on?

David

[rob love]

David

It does translate into NSN 5930-00-242-8427, but since it is a common mil-spec switch, it will have been used on anything that needed a SPDT switch.

[rob love]

Mystery Solved. One of the long time radio guys from here remembered seeing one of these panels on a M37 with the C42 radio setup. The panel was hooked up to the Chorehorse, two banks of batteries, and the C42radio set.

I'll try and post one of the drawings he sent, but it was in PDF.

[Robert Bergeron]

Good news ! Mystery solved .