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Plumber has just completed upgrading heating system which includes 3 zone valves. When completing wiring for zone valves I encountered some strange readings. The switch on the zone valve is supplied with a pernament live(230v AC). When the valve is open the switch closes and switched live goes back to wiring center. My problem is that with the switch open I am getting 70volts AC coming back on the switched live. Disconnected pernament live and 70v disappeared. Verified correct operation of switch. Suspected fault in cable. Connnected with a new cable and same problem exists.
As part of trouble shooting, I connect one core of a short length of 3 core cable to a pernament live. I was then getting 70v AC on the 2 cores which were not connected to anything at either end ! Measurements were taken using a multimeter with CU earth terminal used for Com.
Any ideas on where these voltages are coming form ?
As part of trouble shooting, I connect one core of a short length of 3 core cable to a pernament live. I was then getting 70v AC on the 2 cores which were not connected to anything at either end ! Measurements were taken using a multimeter with CU earth terminal used for Com.
Any ideas on where these voltages are coming form ?