Lennox chiller Re-wire

[james10]

Some technical help needed on this one folks
i have a lennox wa370 water chiller on site using 6 copeland scroll compressors with tev's the control pcb's were destroyed by a dodgy tech so i have the task of rewiring the chiller using mechanical controlls as the parts from lennox are over priced and a too long of a lead time, also the client wants the chiller running asap regardless of cost.
so far i have fitted a carel Ir32 control for the compressors and fan speed control for the fans with flow and hp-lp switches wired in series the chiller runs fine with regards to temperatures the problem i have is the control is constantly starting and stopping the compressors when they near setpoint i have tried various setting in the controls to prevent this diff dead bands etc so what i need to do is fit anti recycle timers having trawled the rs website i can't seem to find one suitable i need a 24v timer with a minimun of 15mins restar time if anyone can recomend a timer to use i would be very gratefull
Thanks in advance

[Brian_UK]

RS are the people you need but you can get an ON-DELAY timer from most good electrical wholesalers.

You need function type 111, as here

http://uk.rs-online.com/web/generalDisplay.html?id=info/timer

Something like this ?

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=0214640

[james10]

cheers Brian i got some boyce control m1mft's they did the job chiller runs better now than it ever did with lennox controls

[Brian_UK]

Well done, some decent job satisfaction in this one I expect.

[Paul J]

if you used the IR32 model carel it has multiple outputs, you can have minimum on and off times for each output. C8 is the minimum off time of the same output, C9 is the minimum on time of the same output, cheers Paul:cool:

[james10]

if you used the IR32 model carel it has multiple outputs, you can have minimum on and off times for each output. C8 is the minimum off time of the same output, C9 is the minimum on time of the same output, cheers Paul:cool:
cheers paul i did try that but the control seemed erratic also the temperature sensor was not showing correctly turns out the control i bought 1r32 was superceeded 6 years ago and the one i have is faulty so i'm swapping it out for two, two stage controls

[Paul J]

To explain the carels use this
First two letters
IR= Infra red programmable

Second two numbers
32= old series
33= new series

third letter
V= 1 output
W=2 outputs
Z= 4 outputs

Fourth number
0=NTC temp input
1=PT100 temp input
2=Thermocouple input J/K
3=4/20mA input

So an IR32Z3 will take a 4/20mA input say from a pressure transducer and has 4 digital outputs for say start comp and 3 stages of loading
cheers Paul:cool:

[james10]

Thanks for the info paul i fitted two controlers to the unit it's been running nicely ever since (fingers crossed)