11
JOHNSON CONTROLS
FORM 155.21-W2 (1209)
The maximum rate at which the OptiView control pan
‑
el will accept Remote Steam/Hot Water Limit setpoint
pulses is one pulse each 60 seconds. Following a remote
setpoint pulse, the Steam/Hot Water Limit setpoint
changes to the value corresponding to the pulse‑width.
if a second reset pulse is not received within 30 minutes
of the first pulse, the Steam/Hot Water setpoint reverts
to the programmed maximum load limit setpoint. If
the “Pulldown Demand Limit” has been programmed
and the unit was started and has run less than the Pull
‑
down Demand Limit Timer setpoint, then the unit will
be steam/hot water limited by the lower of the Pull
‑
down Demand Limit and the Remote Steam/Hot Water
Limit. The Pulldown Demand Limit will automatically
transfer control of Steam/Hot Water Limit function to
“
REMOTE
” at the end of its programmed timed cycle
with the unit in the "REMOTE" mode.
REMOTE LEAVING CHILLED LIQUID
TEMPERATURE SETPOINT
Remote Leaving Chiller Liquid Temperature setpoint
allows an operator to change the leaving chilled liquid
temperature from a remote location. Before this can be
accomplished the “Remote Reset Range” must be set
‑
up locally on the OptiView panel by a qualified YORK/
Johnson Controls service technician. This parameter is
the maximum allowable offset of the leaving chilled
liquid setpoint when operating in the Remote mode.
This offset is either 10°F or 20°F as programmed. If
not programmed, the default value is 20°F. This value
is added to the operator programmed “Leaving Chilled
Liquid Temperature Setpoint” (base) and the sum equal
the temperature range in which the setpoint can be reset.
For example, if the operator has locally programmed
a setpoint for 44°F (base) into the OptiView control
center, and the “Remote Reset Range” is programmed
to be 10°F, then the energy management system can
remotely reset the setpoint over the range of 44°F to 54
°F (44 + 10 = 54).
the Remote leaving Chilled liquid
temperature setpoint cannot be set
lower than the base setpoint value. the
base or locally programmed setpoint is
always shown in the “local lCHlt
Setpoint” box in the lower left corner
of the Evaporator / Absorber screen.
REMOTE LEAVING CHILLED LIQUID
TEMPERATURE SETPOINT
(CONTROL SIGNAL; ANALOG, 0‑10VDC)
Remote Leaving Chilled Liquid Temperature setpoint
can be accomplished by supplying (by others) a con
‑
stant 0-10VDC signal to the OptiView control center.
The Leaving Chilled Liquid Temperature setpoint is
programmable over the range of 40°F to 97°F (if Re
‑
mote Reset Range is 20) otherwise 87°F will be the top
end of the range. The OptiView control center must be
configured appropriately to accept the desired signal
as follows:
• The appropriate signal source mode must be se
‑
lected. It is recommended that a qualified YORK/
Johnson Controls service technician accomplish this
in the local/service mode on the OptiView control
center. Analog mode must be selected when using
a 0-10 voltage.
• Microboard program jumper JP24 must be removed
to accept the analog signal. it is recommended that
a qualified YORK/Johnson Controls service techni
‑
cian position this jumper.
FIG. 18 –
REMOTE LEAVING CHILLED LIQUID
TEMPERATURE SETPOINT WITH
0-10VDC SIGNAL
8
J7
+
-
9
LD14446
As shown above, connect the input to microboard J7-8
(signal) and J7‑9 (ground). The leaving chilled water
can then be changed remotely. It cannot be changed
lower than the locally set (base) setpoint nor can it go
any higher than the remote reset range value. if the
OptiView panel is taken out of analog mode for any
reason, the setpoint will revert back to the locally pro
‑
grammed setpoint.
