TheMac Posted January 2 Share Posted January 2 Good day I am running 8x (4 x Lives, 4 x Neutrals) 1.5mm2 GP Wires in a conduit across a distance of about 12 metres. These wires connect to 4 x DIN Rail 220V LED Indicators. If I power on one of the indicators then another one has a slight glow. I measure 5V across that lightly glowing indicator (not supposed to be on). I made sure to test that none of the wires have any leakage (continuity) between them so may I then assume this to be induced by the powered line? If so, am I correct in saying that I have at least two options? Break the neutrals also when switching off the indicators. Add a strong enough resistor to minimize that induced voltage. Thank you Quote Link to comment Share on other sites More sharing options...
TaliaB Posted January 2 Share Posted January 2 3 hours ago, TheMac said: Good day I am running 8x (4 x Lives, 4 x Neutrals) 1.5mm2 GP Wires in a conduit across a distance of about 12 metres. These wires connect to 4 x DIN Rail 220V LED Indicators. If I power on one of the indicators then another one has a slight glow. I measure 5V across that lightly glowing indicator (not supposed to be on). I made sure to test that none of the wires have any leakage (continuity) between them so may I then assume this to be induced by the powered line? If so, am I correct in saying that I have at least two options? Break the neutrals also when switching off the indicators. Add a strong enough resistor to minimize that induced voltage. Thank you I once had a project with 24VAC inputs on a PLC which were connected to wires that ran in the same conduit with conductors for a 100HP 400V motor, about 45m run length. Once the pump turned on, the current in the motor leads induced enough voltage on the control wires that the PLC inputs would remain Hi even when the circuit was opened at the other end (limit switch on a control valve) so the pump would never shut off. It did not induce enough to energize a Lo input, but it was enough to prevent a Hi input from being read Lo when opened. A simple dropping resistor solved the problem. I interpreted that the PLC had almost zero burden but had there been more, as evidenced by the resistor, it dropped to being immeasurable. TheMac 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.