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i have a square d ccn240 contactor. it is supposed to be used between a wall situated thermostat and underfloor heating mats.
i know that the contactor is supposed to be normally open so that when the switch line from the thermostat tells the contactor to go on, the contactor should close and the power should go to the mats.
however, this is not happening, and the contactor seems to be closed all the time. although once, after turning the power on at the fuse board, it made a noise and didnt call for power initially. then, when the thermostat sent the signal via the switch line, it made a noise and closed and the mats received power. when the thermostat later tried to tell the contactor to open again (ie so the mats would switch off), the contactor made a funny noise and then seemed to close again, as if maybe it was broken inside, is this possible?
or have i purchased a normally closed contactor? there is no such info on the internet or with the product.
ps.
a. the contactor is 40 amp rated but i probably only need 13a or 16a, so if i am buying a new contactor, which one should i buy?
b. does it matter that the thermostat is powered by the same fuse as the contactor/matting? i appreciate that the thermostat should be supplied from a lower rated fuse on the fuse board but at the moment there is no other way to power it. therefore i just want to check that having them both powered off the same fuse/cable isn't causing these problems.
thanks
i know that the contactor is supposed to be normally open so that when the switch line from the thermostat tells the contactor to go on, the contactor should close and the power should go to the mats.
however, this is not happening, and the contactor seems to be closed all the time. although once, after turning the power on at the fuse board, it made a noise and didnt call for power initially. then, when the thermostat sent the signal via the switch line, it made a noise and closed and the mats received power. when the thermostat later tried to tell the contactor to open again (ie so the mats would switch off), the contactor made a funny noise and then seemed to close again, as if maybe it was broken inside, is this possible?
or have i purchased a normally closed contactor? there is no such info on the internet or with the product.
ps.
a. the contactor is 40 amp rated but i probably only need 13a or 16a, so if i am buying a new contactor, which one should i buy?
b. does it matter that the thermostat is powered by the same fuse as the contactor/matting? i appreciate that the thermostat should be supplied from a lower rated fuse on the fuse board but at the moment there is no other way to power it. therefore i just want to check that having them both powered off the same fuse/cable isn't causing these problems.
thanks