I bought a current sensing relay model A50 to assist in control of my add-on
humidifier, yeah I have an old furnace.
I installed the senser over the common wire going to the blower motor, at
least 8" away from the nearest transformer (it says at least 3" in the
instructions). When the blower comes on the humidifier comes on as it
should, but when the blower shuts off, the humidifier continues to run, so
the A50 is not cutting the circuit like it should. If I shut the main power
off to the furnace and turn it back on, then about 4 of out of 5 times the
A50 recognizes the power loss and turns off the humidfier. Even if I remove
the A50 from the common wire while the blower is on and hold it away from
the furnace it does not recognizes the power loss (it must only monitor for
Per the instructions, "wire lead must carry min of 4 amps for proper
operation, if not wrap lead wire around bracket two or more times." OK,
right now I don't know about the 4 amps, but if I have to wrap the common
around this bracket then I will have to splice it and insert a fews inches
of wire. Thats not a big deal, unless I've got a bad senser. Any Ideas?