actuator change

carol_3

Sorry, I don't know much about DDC either. Perhaps you could find someone at your Belimo distributor?

bluenose_30

actuator change

I'll start with the fact that I don't know alot of DDC controls, I'm just a heating tech.I have a honeywell ML7425 actuator on a honeywell V33xx valve and I want to change it to a Belimo actuator(NFV24_MFT).I have a question about the wiring, at present the honeywell is wired with one wire on "+",one wire on "T1" , one wire on "Ts" and jumpers between "Ts,T2&"-". This is 2-10 vdc control,which has me a little losted because there doesn't seem to be a "-" dc source(it was working until the gears in valve stripped for the second time in 2.5 yrs).Can I wire the Belimo with 3 wires? and jumper the "-" from my 24 ac signal like the honeywell is wired or should I find/ get another wire pulled.
Any help would be appreciated. Thanks

Empire_2

bluenose

Almost sounds like your drive on the actuator is not shutting down on power open or power close. Why is the gearing stripping???

Mike T.

BAB

Older Honeywell Thermostat

I have an old Honeywell programmable thermostat that works ok but may be turning the steam boiler on or off more often then necessary. The face of the unit swings on the left & then clips on & off. When the face is off there is a slot with two screws that can be adjusted for a "Hot Water Tank" or a "Forced Air Furnace" or "Others" and some other choices. Be adjusting the two screws in or out the stat then has it's "heating cycle" changed from 6 times per hour or to 4.5 times per hour or 3 times per hour, etc. Is this heating cycle feature turning the boiler on or off when I do not want it to, ... what is the purpose of this feature? I am home & the stat is at work.

BAB

Old Honeywell Programmable Thermostat

I have an old Honeywell programmable thermostat that works ok but may be turning the steam boiler on or off more often then necessary. The face of the unit swings on the left & then clips on & off. When the face is off there is a slot with two screws that can be adjusted for a "Hot Water Tank" or a "Forced Air Furnace" or "Others" and some other choices. Be adjusting the two screws in or out the stat then has it's "heating cycle" changed from 6 times per hour or to 4.5 times per hour or 3 times per hour, etc. Is this heating cycle feature turning the boiler on or off when I do not want it to, ... what is the purpose of this feature? I am home & the stat is at work.

Empire_2

T-Stat

That is actually your anticipation setting. I never liked that set up from the beginning. It is fixed and cannot learn for changing indoor temp swings. Most t-stats now go with a proportional drop, which is adjustable from 1* to 3* .....3 giving you a longer run time, but allowing more of a drop which may be unacceptable.

My .02 Mike T.