50
RTAD-SVX01F-E4
Installation - Electrical
Specification for Free Cooling units:
1. External Auto/Stop (terminals
A70 J8-IDH14 and 6X2-1).
This input is supplied by the field.
A contact closure will start the
chiller water pump and chiller, via
the UCM-CLD and A70 (regulation
for Free Cooling mode) pump
control contacts. Opening the
contact will put the operating
compressors into "Run:Unload"
mode and initiate a timing period
(1 to 30 minutes, adjustable
through the Clear Language
Display). This will delay
termination of the chilled-water
pump operation via the UCM
pump control contacts. Examples
of the input terminals 1UTB3-3
and -4 would be a time clock,
ambient thermostat, building
automation system, etc.
2. UCM-CLD and A 70 Pump Control
Contacts (Terminals A70 J14-C7
and -NO7)
This output is a set of contacts
that will close, starting the chilled-
water pump when the external
Auto/Stop contacts are closed.
When the contacts are opened,
1 to 30 minutes later (adjustable
through the Clear Language
Display), the UCM-CLD and A70
pump control contacts open.
3. Proof-of-Chilled-Water-Flow
Interlock (Terminals A70 J18-
IDC13 and -ID13H)
This terminal must be field-
installed. Contact closure between
the terminals indicates proof of
chilledwater flow. Examples of
this are a pump starter auxiliary
contact, flow switch, differential
pressure switch, or a contact from
a building automation system.
Opening of this contact will
immediately shut down the chiller
and initiate an automatic reset
diagnostic, indicating loss of
chilled-water flow.
4. Free Cooling enable input
(terminals A70 J5-IDI and 6X2-4).
This input is supplied by the field.
This is a digital input that
indicates if the Free Cooling mode
is validated, or if only the
Compressor mode must run. If
this input is open, then only the
Compressor mode will be
available. If this input is close,
then the control will select the
best mode (Free Cooling mode or
Compressor mode).
