Honeywell ST 9162 EFT

carol_3

For Roger I have an email address of rogdarschill@comcast.net. It worked last summer!

Unknown

What are the expected voltages

from the ST 9162 to the ECM direct current motor control. I have been in the past getting around 14 volts AC. A recent check on two of them showed voltages of 35 to 40 volts. Any ideas, what is also interesting is they work on both voltages without failure. These are two jobs that I am monitoring for other problems and just wondered about these voltage. That is from the P2 connector on that board by the way. It is being used with the Two Stage SmartValve SV9540 Q.

Unknown

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superMARKet

PWM

Tim, I think (but hey, what do I know?) that the connector you're talking about drives ECM controllers in variable-speed mode. The speed output to an ECM controller is delivered pulse-width modulated (PWM), at some low-ish DC voltage (10?) Most volt/multimeters don't know anything about PWM and happily misinterpret it as AC, giving false readings.

Sound good?

Unknown

You are correct Mark

that signal is piggybacked on the actual voltage signal to the ECM controller. Honeywell at one time gave voltage readings (AC) for this control to be 14 volts AC plus or minus .1 volt. I am getting readings on several jobs that are erratic but there is no visible problem with the system. I thought Carol could check with Honeywell Engineering for a correct answer as to what we should measure. These are on a Comfortmaker Furnace NTVM/VNK series.

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carol_3

Tim--because of your past affiliation with the Honeywell Source program, you probably have closer ties with the OEM gas and ignition folks at Honeywell than I do. I suggest that you network with your contacts and get an answer!

Unknown

Carol, I talked with

Honeywell Tech services and they could not give me an answer. I called Bill Ribble he was not sure. I then tried to get hold of Jim Cole and Roger Schilling but my phone numbers are out of date I guess. I left Source in 1999 so many of those folks have retired.

Any help with a name/number would be greatly appreciated.

Unknown

Interesting I just had

another one of these with different voltages and no one can give me an answer - very frustrating to say the least.

Anyone have any ideas?

Unknown

Thanks Carol

that is a different one than I had. I will try and reach him.