X-10 Mods - SC546 - Chime Module

Here we explain how to modify a USA 115V SC546 Chime module to operate at 230V.

Introduction

I have successfully completed this modification once, however, and I accept no responsibility for the effects of anyone making these modifications.   You follow these instructions at your own risk.

Modification Steps

1. Open the X-10 module by removing the four screws and take out the Printed Circuit Board (PCB).
2. Change the big, usually blue, 1.0uF 250V capacitor normally marked 1.0K 250V to 0.47uF 400V.
3. Change the 330k 0.25W resistor close to the incoming power to 330k 0.5W.
4. Change the MOV close to the incoming power from 130V RMS to 250V RMS if you have 220V and to 275V if your power supply is 230V or 240V.
5. Change the 10 Ohm 0.5W resistor mounted close to the small transformer to 22 Ohm 1W.
6. Change the incoming plug or use an adapter, reassemble.

If you attempt these modifications, please let me know your results, and read the warning on the X-10 and 115V & 230V page.

Comments received at Redoak

None so far.