Troubleshooting SCRs

Thread Starter

Erin G.

Joined Mar 3, 2005
Does anyone know of a quick way to bench test an SCR using a Fluke 787 or or similar meter(s)? SCR is a Westcode model N350CH16, one that looks like a white hockey puck. All ideas are welcome,...


Joined Jan 22, 2004

thanks to "Joe Jester" for pointing out this site.

what is have prepared here is a ready to print version of the above topic.


Joined Jan 6, 2004
Hola Erin,

In the need to test an SCR when at sea, not being an electrician, I've just recalled what I knew about them and did this:

The multimeter ready to measure resitance in series with anode and cathode, closing the circuit. Initially showing very high resistance.

Then a small 1,5 battery between cathode and gate (+ to gate). When applied, the multimeter commenced to show low resistance, meaning that the SCR was triggered thus, conducting.

The battery due to its inherent internal resistance provided current limitation. If you use a power supply, do limitate using a suitable value resistor.

Also I repaired the flip flop driving the of the main engine alarm panel, but that, we leave it for another posting...