For 26 years the villagers at our rural vocational training center have used a 220VAC - 12VDC battery charger/booster that uses 2 Otter controls (bimetallic automatically resetting circuit breakers). A couple weeks ago the villagers used it and it emitted some smoke and the primary coil became hot. The rectifier bridge was cracked so I replaced it.
The secondary circuit uses an Otter V1 series bimetallic switch (The code by the terminals on the V1 is: 1603781.). But the secondary circuit does not become hot; I don't think there is a problem there. Even with no load, turning on the charger to Normal or Boost creates smoke within a minute and heats up the primary windings. I measured a/c amps when I turned it on: I got a transient starting about 3.5 amps going down to .9 or 1.1 amps (normal/boost). The primary circuit has a G-series Otter Control (marked with the code: 18G4744).
I contacted Otter to see how to check the switches. They said,
With it disconnected and on the bench; the 2 primary circuits measure resistance of 12.8 and 13.3 Ohms. The secondary windings measure 2.5 Ohms. How can I know if the windings are still good?
Can you give me a pointer as to how to diagnose and bring our handy battery charger back to life? The villagers here use it to power a vibrating table with which they make concrete ornamental paving slabs. Sales of these slabs keeps them fed and puts their children through school. Thank you for any help you can render.
The secondary circuit uses an Otter V1 series bimetallic switch (The code by the terminals on the V1 is: 1603781.). But the secondary circuit does not become hot; I don't think there is a problem there. Even with no load, turning on the charger to Normal or Boost creates smoke within a minute and heats up the primary windings. I measured a/c amps when I turned it on: I got a transient starting about 3.5 amps going down to .9 or 1.1 amps (normal/boost). The primary circuit has a G-series Otter Control (marked with the code: 18G4744).
I contacted Otter to see how to check the switches. They said,
"The G & V series are very simple, reliable & robust safety cut-outs. They are there to prevent a fire in a fault condition. They carry the current, but do not control the current. The bimetals are set to operate at a certain temperature. The operating temperature will be reached in a fault condition via the temperature feedback from the winding & the heating caused within the bimetal by the carry current."
This does not sound correct to me. What do you think? Otter makes both types of devices. It seems very strange to me for a battery charger circuit to have a fire protection device. If it is a thermostat then if the primary coil heats up enough to smoke I would expect it to cut out. I tried cleaning the contacts with fine sand paper with no change in symptoms. I tried to use a lighter to heat both the primary and secondary circuit Otter controls for some seconds. Neither opened their contacts. Perhaps I didn't heat them long enough.With it disconnected and on the bench; the 2 primary circuits measure resistance of 12.8 and 13.3 Ohms. The secondary windings measure 2.5 Ohms. How can I know if the windings are still good?
Can you give me a pointer as to how to diagnose and bring our handy battery charger back to life? The villagers here use it to power a vibrating table with which they make concrete ornamental paving slabs. Sales of these slabs keeps them fed and puts their children through school. Thank you for any help you can render.