Avometer Model 7 Mk2 Overload Cut-Out Mechanism

The AVO 7 Mk2 overload cut-out switch is extremely sensitive, and sometimes damage to it indicates a burnt meter. Occasionally, I have come across meters where the switch would not remain in the locked position. The cut-out mechanism relies on smooth surfaces, which are parts with chrome plating. Usually dried grease on these surfaces is enough to prevent it from locking.

A heavy overload will cause the cut-out knob to spring up thus separating the contacts and disconnecting the meter from the circuit. After removing the overload, the cut-out will reset with the meter lying down face upward. You can also get a meter on eBay with burnt cut-out switch contacts, and in such a circumstance, the meter is virtually useless.

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