W7100 reset

[mrhvacmechanic]

Can anyone tell me EXACTLY how the reset dial and return air sensor operates on a W7100 cooling only discharge air set up?
Dis spt 55F
Reset pot 70F
Band 10F
Two stage unit cool only

PS I understand how warm up and heat work, Can you tell me Eaxctly how much reset above the discharge 55F setpoint I will have with the above settings? I have been told thet you divide 3 into the band , so that would give me 3.33F set up per degree over the reset 70F setting???

[Freeze Stat]

It's been a while since I've played with the W7100. You may be reading the reset dial incorrectly. The outer ring of numbers is cooling reset, thus your 70*F setting is really 17.5* of cooling reset. This raises your discharge air setpoint 17.5* (72.5*F). That's too much reset. You can download W 7100 literature at the Honeywell website, http://www.customer.honeywell.com

[hanknerd]

Freeze is correct about the reset, cooling value is on the outside and heating is on the inside ring. Cooling reset limited to 20, heating is up to 80.
Your control band setting is the amount of change in discharge temperature that will turn on/off stages of cooling. Take your reset setpoint, add control band divided by 2 and that will give you the value that your next stage of cooling will cycle on. Control band has no effect on setpoint, only your resetting sensor does (sensor connected to terminals 6 & 7).
Here's a direct link to data on the W7100:
http://hbctechlit.honeywell.com/tech...0s/60-2507.pdf
It describes in words and diagrams control band, reset and gives checkout and troubleshooting data.

[NormChris]

Just a point of information. Honeywell no longer makes the W7100 discharge air controller.

I have been trying to find out what they are using for a replacement or is there no replacement?

[maxster]

have you worked with this controller,you can do staging with a discharge air sensor up to 4 stages but the econo off the old 7100 is lost on it http://hbctechlit.honeywell.com/tech...0s/63-2489.pdf

[mrhvacmechanic]

Thanks Guys,
I have checked control and it is operational. I have worked with it before but not to often with reset.

I also heard HW is discontinuing both the W7100 and the W973, probably the best two controlls they ever made. Our rep is pushing all the DDC equipment to take the place of them. Too bad. I am with the times but when you have a simple application on a indoor unit or rtu, these two controls were excellent.Especially when you install a economizer set-up.

To replace the W973 were are given a stat and one of there economizer modules (W7200??)with 2-10 vdc motors. Here also eventually phasing out the 135 Ohm motors, wich I beleive only Belimo is now making.

You know, even thou these controlls have been around, they were excellent and do the job.