cad cell readings

jaybee

I was trying to get ohmn readings on a cad cell.Acording to what i have read when a light is not present your reading should be 100,000 and when light is present should read lower then 1500.With the burner not running (meter set 200k ohmns)i got 15.7 and when i turned the burner on my ohmn readings went up and down .Was i checking it wrong?

John@Reliable_9

Cad cell readings

1. Remove wires from F-F 2. Now check leads to cell 3. Start burner anything over 1500-1600 replace cell. PS make sure meter is set to right scale, hope this helps John@Reliable

Walter_3

maximum flow

Hi guys. I need some answers from a pros. Assuming I have a boiler 100,000 BTU input and an indirect water heater 98% efficiency.

What is the maximum flow in gallons/min can I have trough the indirect water heater to have endless hot water? Please explain.

Thanks

Walter_3

maximum flow?

Hi guys. I need some answers from a pros. Assuming I have a boiler 100,000 BTU input and an indirect water heater 98% efficiency.

What is the maximum flow in gallons/min can I have trough the indirect water heater to have endless hot water? Please explain.

Thanks

john_35

cad cell

The reason the readings fluctuate is the intensity of light produced by the flame fluctuates. It's more noticeable on conventional burners because the flame is less stable. I prefer to use an analog meter for cad cells because most digital ones have a feature called auto-ranging that makes the readings (sometimes) fly all over the place. That's probably what was happening to you. You can get a cheap analog meter that's relatively accurate at Sears or Radio Shack. I like to see the reading below 800 ohms to be sure I'm not getting false lock-out, but there are times when you can't get it below 1000. Always adjust the flame first and re-check the cell. More often the combustion quality is making the cad cell read high.

jaybee

cad cell readings

THANKS, you guys are terrific!!!!!!! THANKS