Finished the CP build - no power to components

**Spike Innovations** · Posted: Wed Mar 09, 2011 11:15 pm Post subject:

Definitely sounds like something is still wrong... Is this voltage tested with the element select switch on and the pid's not cycling?

Mike

**kal** · Posted: Mon May 30, 2011 5:40 pm Post subject:

Any update to this? Did you fix it? How?

Someone else emailed me that they only get 70-75V to the Boil & HLT relays so it sounds like there's likely a wiring problem that people have in common.

Kal

iowabrewer · Joined: 16 Dec 2010 Posts: 53 Location: stranded in Iowa

I had an electrician buddy do a little check the Solid-State Relay wiring (SSR’s) when I had the voltage problem. This is what he found. The SSR's apparently have a minimum operating current (typically around 100mA) to fully turn on. He thinks it is due to how the internal semiconductor devices interact with one another. Here is a guess at what was happening with your system when the only load was the indicator light.

Assuming that the indicator light was rated at 1 watt at 240V (just a guess), it would have a resistance of 57.6K ohms. We measured the voltage to be 75V across the light. This would mean that the current in the circuit was around 1.3 mA (75V / 57600 ohms). Since this was below the minimum operating current of 100 mA, the SSR must have turned on partially with an internal resistance of about 18K ohms ((57600 ohms/75 V)* 240 V).

When we hooked CP to a element and put a load on it (boiled water) the voltage was fine.

Keep in mind, I am only the messenger/user. I hope this helps.

**kal** · Posted: Tue May 31, 2011 2:43 pm Post subject:

Thanks. What I find odd is that my SSRs when off measure about 12-13V. These other SSRs that the guy was using (like yours) have around 75V when off. That's a major difference.

Wth 75V across the yellow/orange element lights are lit about 1/2 way whereas with mine at 12-13V they're pretty much off.

Strange.

Kal