Operation Features:
2 chiller lead/lag
addition of a third chill er for backup
manual rotation of lead chiller
load balancing if conf ig ured
staggered restart of the chill ers after a p ower failure
chillers may be piped in pa rallel or in series chi lle d water flow
Common Point Sensor Insta llation
Lead/lag operation do es not require a common chil led water point sensor . Common point
sensors can be added to the 8-input option modu le, if desired. Refer to th e certified drawings f or
termination of sensor leads.
Note: If the common point sensor option is chosen on a chilled water system, both machines
should have their own 8-in put option module and c om m on point sensor instal led . Each
machine will use its ow n c om m on point sensor for control, when that machine is desi g-
nated as the l ead chiller. T he PIC cannot read the value of common poi nt sensors
installed on other machines in the chilled water system.
When installing chiller s in s er ie s, a common point sensor sho uld be used. If a common point
sensor is not used, the lea ving chilled water sens or of the upstream chiller m us t be moved into
the leaving chilled wa te r pipe of the downstream ch ill er.
If return chilled water c on trol is required on chill ers piped in series, the c om m on point return