Carrier AQUAZONE 50PTH - Manual (Page 42)

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vide cooling to the space when required. Should the capacity
be insufficient for a period greater than 5 minutes, or should a
high humidity condition occur, then the compressor will be
started to satisfy the load. Should the SAT reach the minimum
cooling SAT limit, the economizer valve will close during
compressor operation.
Heating — Additionally, the economizer control will open the
water valve should the entering water loop temperature be suit-
able for heating (at least 5 F above space temperature) and
heat is required. The valve will be controlled in a similar man-
ner except to satisfy the heating requirement. Should the coil
capacity be insufficient to satisfy the space load for more than
5 minutes, then the compressor will be started to satisfy the
load. Should the SAT reach the maximum heating SAT limit,
the economizer valve will close during compressor operation.
DEMAND LIMIT — The WSHP Open controller has the
ability to accept three levels of demand limit from the network.
In response to a demand limit, the unit will decrease its heating
set point and increase its cooling set point to widen the range in
order to immediately lower the electrical demand. The amount
of temperature adjustment in response is user adjustable for
both heating and cooling and for each demand level. The re-
sponse to a particular demand level may also be set to zero.
CONDENSER WATER LINKAGE — The control pro-
vides optimized water loop operation using an universal con-
troller (UC) open loop controller. Loop pump operation is auto-
matically controlled by WSHP equipment occupancy sched-
ules, unoccupied demand and tenant override conditions.
Positive pump status feedback prevents nuisance fault trips.
The condenser water linkage operates when a request for con-
denser water pump operation is sent from each WSHP to the
loop controller. This request is generated whenever any WSHP
is scheduled to be occupied, is starting during optimal start (for
warm-up or pull down prior to occupancy), there is an unoccu-
pied heating or cooling demand, or a tenant pushbutton over-
ride. At each WSHP, the water loop temperature and the loop
pump status is given. The WSHP will NOT start a compressor
until the loop pumps are running or will shutdown the com-
pressors should the pumps stop. This prevents the WSHP from
operating without water flow and thus tripping out on refriger-
ant pressure, causing a lockout condition. The WSHP Open
controller control will prevent this from occurring. Also, the
loop controller can be configured to start the pumps only after a
configurable number of WSHPs are requesting operation (from
1-"N"). This can be used to prevent starting the entire loop op-
eration for only one WSHP. Meanwhile, the WSHPs will not
operate if the loop pump status is off and therefore the WSHP
compressor will not run.
COMPLETE C AND DELUXE D BOARD
SYSTEM TEST
Test mode provides the ability to check the control opera-
tion in a timely manner. The control enters a 20-minute test
mode by momentarily shorting the test terminals. All time de-
lays are sped up 15 times. The following operations are com-
mon to both Complete C and Deluxe D controls.
Test Mode — To enter Test mode, cycle the fan 3 times
within 60 seconds. The LED will flash a code representing the
last fault when entering the Test mode. The alarm relay will
also power on and off during Test mode. See Tables 27 and 28.
To exit Test mode, short the terminals for 3 seconds or cycle
the fan 3 times within 60 seconds.
NOTE: The flashing code and alarm relay cycling code will
both have the same numerical label. For example, flashing
code 1 will have an alarm relay cycling code 1. Code 1 indi-
cates the control has not faulted since the last power off to
power on sequence.
Table 27 — Complete C Control Current LED
Status and Alarm Relay Operations
LEGEND
NOTES:
1. Slow flash is 1 flash every 2 seconds.
2. Fast flash is 2 flashes every 1 second.
3. EXAMPLE: “Flashing Code 2” is represented by 2 fast flashes followed by
a 10-second pause. This sequence will repeat continually until the fault is
cleared.
Table 28 — Complete C Control LED Code and
Fault Descriptions
LEGEND

LED STATUS DESCRIPTION OF OPERATION ALARM RELAY
On
Normal Mode Open
Normal Mode with
PM Warning
Cycle
(closed 5 sec.,
open 25 sec.)
Off
Complete C Control is
non-functional
Open
Slow Flash Fault Retry Open
Fast Flash Lockout Closed
Slow Flash Over/Under Voltage Shutdown
Open,
(Closed after
15 minutes)
Flashing Code 1 Test Mode — No fault in memory Cycling Code 1
Flashing Code 2
Test Mode —
HP Fault in memory
Cycling Code 2
Flashing Code 3
Test Mode —
LP Fault in memory
Cycling Code 3
Flashing Code 4
Test Mode —
FP1 Fault in memory
Cycling Code 4
Flashing Code 5
Test Mode —
FP2 Fault in memory
Cycling Code 5
Flashing Code 6
Test Mode —
CO Fault in memory
Cycling Code 6
Flashing Code 7
Test Mode — Over/Under
shutdown in memory
Cycling Code 7
Flashing Code 8 Test Mode — PM in memory Cycling Code 8
Flashing Code 9
Test Mode — FP1/FP2
Swapped Fault in memory
Cycling Code 9
CO — Condensate Overflow
FP — Freeze Protection
HP — High Pressure
LED — Light-Emitting Diode
LP — Low Pressure
PM — Performance Monitor
LED
CODE
FAULT DESCRIPTION
1 No fault in memory There has been no fault since
the last power-down to power-
up sequence
2 High-Pressure Switch HP switch opens instantly
3 Low-Pressure Switch LP switch opens for
30 continuous seconds before
or during a call (bypassed for
first 60 seconds)
4 Freeze Protection Coax
— FP1 FP1 below Temp limit for
30 continuous seconds
(bypassed for first 60 seconds of
operation)
5 Freeze Protection Air Coil —
FP2 FP2 below Temp limit for
30 continuous seconds
(bypassed for first 60 seconds of
operation)
6 Condensate overflow Sense overflow (grounded) for
30 continuous seconds
7
(Autoreset)
Over/Under Voltage
Shutdown "R" power supply is <19VAC or
>30VAC
8 PM Warning Performance Monitor Warning
has occurred.
9 FP1 and FP2
Thermistors are swapped FP1 temperature is higher than
FP2 in heating/test mode, or
FP2 temperature is higher than
FP1 in cooling/test mode.
FP — Freeze Protection
HP — High Pressure
LED — Light-Emitting Diode
LP — Low Pressure
PM — Performance Monitor