help with power source

[brianmay27]

ok. i know it is a weird question but i have a Lorain floral rectifier. model number is a12f50. It should be giving out 56ish volts dc but instead it is giving out 88V dc. Do you know of any why to reduce the voltage? it has to be able to with stand possibly 15 amps. or even better if there is just something i need to change.

[Spyman]

Is this the one ? -> http://swiftindustrialpower.com/integrated/products/dcpowerplants/marconi/pdfs/4_1.pdf

 

The Lorain® model A6F50 and A12F50 rectifiers provide -48 VDC, 6 or 12 amp power for a

broad range of applications.

 

LED indicators on the front panel clearly signal power-on status, rectifier failure, high

voltage shutdown, rectifier failure, and fuse alarm conditions.

 

Inputs

Voltage:

120 (88-132) VAC, single phase

208/240 (176-264) VAC, single phase

Frequency: 47-63 Hz

 

Output

Float/Equalize Voltage: 48 (48.3-58.0) VDC, adjustable

Current:

Model A6F50 — 6 amps

Model A12F50 — 12 amps

Regulation: Steady-state ±1/2% within range of 48.3 to 58.0

volts from no load to full load over the specified input

voltage and frequency ranges.

 

High voltage shutdown circuit causes shutdown if output

voltage exceeds the predetermined (adjustable) value.

 

It looks like a battery charger, some chargers can exceed the output voltage when no battery is connected.

 

But as I read it, the charger should be protected against "to high" output, so it might be broken...

 

What does the LED indicators on the front tell you ?

 

Also "predetermined (adjustable) value" indicates that output voltage is adjustable and could be set to "to high".

(In which case it wouldn't give any alarms or shut down.)

 

Usually the voltage is adjusted by a "hidden" trimmer, (potentiometer), somewhere inside the supplybox but reachable from outside through one of the cooling holes by a very small screwdriver.

 

Please note that poking around in it with a screwdriver when the power is connected is dangerous !!!

(Electric shock and all that.)

[YT2095]

and also there is likely to be a potential between the trimer ring and the case, shorting that could really blow it!

best to take the case off entirely.

sometimes it can be something as simple as dust between the carbon horseshoe track and the trimer ring brush/wiper.

it`s also best to test it with a load also, at those voltages you can get away with an ordinary household light bulb.