Carrier 50YFV Installation, Operation And Maintenance Instructions page 25

R e s i d e n t i a l D i g i t a l P a c k a g e d U n i t s G T- P B S e r i e s - 6 0 H z P u r o n
Installation
The HWG is controlled by two sensors and the DXM2 micro-
processor control. One sensor is located on the compressor
discharge line to sense the discharge refrigerant tempera-
ture. The other sensor is located on the HWG heat exchang-
er's "Water In" line to sense the potable water temperature.
WARNING!
WARNING! UNDER NO CIRCUMSTANCES SHOULD
THE SENSORS BE DISCONNECTED OR REMOVED.
FULL LOAD CONDITIONS CAN DRIVE HOT
WATER TANK TEMPERATURES FAR ABOVE SAFE
TEMPERATURE LEVELS IF SENSORS DISCONNECTED
OR REMOVED.
The DXM2 microprocessor control monitors the refrigerant
and water temperatures to determine when to operate
the HWG. The HWG will operate any time the refrigerant
temperature is suffi ciently above the water temperature.
Once the HWG has satisfi ed the water heating demand
during a heat pump run cycle, the controller will cycle the
pump at regular Intervals to determine if an additional HWG
cycle can be utilized.
When the control is powered and the HWG pump output is
active for water temperature sampling or HWG operation,
the DXM2 status LED will slowly fl ash (On 1 second, Off 1
second).
If the control has detected a HWG fault, the DXM2 status
LED will fl ash a numeric fault code as follows:
High Water Temperature (>160ºF)
Hot Water Sensor Fault
Compressor Discharge Sensor Fault
Fault code fl ashes have a duration of 0.3 seconds with
a 10 second pause between fault codes. For example, a
"Compressor Discharge sensor fault" will be six fl ashes 0.3
seconds long, then a 10 second pause, then six fl ashes
again, etc.
WARNING!
WARNING! USING A 150°F SETPOINT ON THE
HWG WILL RESULT IN WATER TEMPERATURES
SUFFICIENT TO CAUSE SEVERE PHYSICAL INJURY
IN THE FORM OF SCALDING OR BURNS, EVEN
WHEN THE HOT WATER TANK TEMPERATURE
SETTING IS VISIBLY SET BELOW 150°F. THE 150°F
HWG SETPOINT MUST ONLY BE USED ON SYSTEMS
THAT EMPLOY AN APPROVED ANTI-SCALD VALVE
(PART NUMBER AVAS4) AT THE HOT WATER
STORAGE TANK WITH SUCH VALVE PROPERLY
SET TO CONTROL WATER TEMPERATURES
DISTRIBUTED TO ALL HOT WATER OUTLETS AT A
TEMPERATURE LEVEL THAT PREVENTS SCALDING
OR BURNS!
Figure 22: Anti-Scald Valve Piping Connections
VALVE PIPING
CONNECTIONS
HOT WATER
Hot Water Generator settings are determined by DIP
switches 3-2, 3-3, and 3-4.
DIP 3-2 controls the HWG Test Mode. It provides for forced
operation of the HWG output, activating the HWG pump for
up to fi ve minutes. ON = HWG test mode, OFF = normal
HWG operation. The control will revert to standard operation
after fi ve minutes regardless of switch position.
5 fl ashes
DIP 3-3 determines HWG set point temperature. It provides
6 fl ashes
for selection of the HWG operating set point. ON = 150°F
6 fl ashes
(66°C), OFF = 125°F (52°C).
DIP 3-4 is for the HWG status. It provides HWG operation
control. ON = HWG mode enabled, OFF = HWG mode
disabled. Units are shipped from the factory with this switch
in the OFF position.
Figure 23: Hot Water Generator Settings
Hot Water
Generator
Settings
Hot Water Generator
ANTI-SCALD
CHECK VALVE
ANTI-SCALD
VALVE
C
M
TO HOUSE
H
WATER HEATER
P2
AL2
R
NSB JW1
Alarm
Relay
C
Fault
ESD
OVR
H
Off On
A
S3
P3
R
NO1
NC1
Acc1
COM1
Relay
NO2
NC2
COM2
Acc2
R Relay
P11
AO2 Gnd
®
R e v : 4 A p r i l , 1 4
COLD WATER
SUPPLY
Gnd
NC
Micro
1
HP
U1
HP
LP
Status
LP
LT1
LT1
LT2
LT2
JW3
RV
Off On
RV
CO
12
Off On CO
P7
RV
Relay
CCH 1
24Vdc
Relay
S2
EH1
A0-1 A0-2
4
EH2
S1
P6
Comp
Relay
CCG
CC
P10 P9
T1 T2 T2 T3 T3 T4 T4 T5 T5 T6 T6
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