WAT E R - S O U R C E H E AT P U M P S
JRC-Series
R e v. : D e c e m b e r 8 , 2 0 2 1
I n s t a l l a t i o n , O p e r a t i o n , M a i n t e n a n c e
26
DXM Controls
Description of
Operation
Status LED
(green)
Test LED
(yellow)
Fault LED
(red)
Alarm Relay
Normal mode
On
-
Off
Open
Normal mode with UPS
On
-
Flashing Code 8
Cycle (closed 5 sec,
open 25 sec)
DXM is non-functional
Off
Off
Off
Open
Fault Retry
Slow Flash
-
Flashing fault code
Open
Lockout
Fast Flash
-
Flashing fault code
Closed
Test Mode
-
On
-
-
Night Setback
Flashing Code 2
-
-
-
ESD
Flashing Code 3
-
-
-
HP Fault
Slow Flash
-
Flashing Code 2
Open
LP Fault
Slow Flash
-
Flashing Code 3
Open
LT1 Fault
Slow Flash
-
Flashing Code 4
Open
LT2 Fault
Slow Flash
-
Flashing Code 5
Open
CO Fault
Slow Flash
-
Flashing Code 6
Open
Over/Under Voltages
Slow Flash
-
Flashing Code 7
Open (closed after 15
minutes)
Notes:
a) Codes will be displayed with a 10 second LED off period.
For example: Code 3= flash 3 times, off for 10 seconds, flash 3 times, off for 10 seconds, etc…
b) Slow flash will be 1 flash per every 2 seconds.
c) Fast flash will be 2 flashes per every 1 second (same as currently is).
Invalid T-stat Inputs
Flashing Code 4
-
-
-
DXM Control -
For detailed control information, see DXM
AOM (part #97B0003N13), Lon controller AOM (part
#97B0013N01) or MPC AOM (part # 97B0031N01).
- Slow Flash = 1 flash every 2 seconds
- Fast Flash = 2 flashes every 1 second
- Flash code 2 = 2 quick flashes, 10 second pause, 2
quick flashes, 10 second pause, etc.
- On pulse 1/3 second; off pulse 1/3 second
Field Selectable Inputs -
Test mode: Test mode allows
the service technician to check the operation of the
control in a timely manner. By momentarily shorting the
test terminals, the DXM control enters a 20 minute test
mode period in which all time delays are sped up 15
times. Upon entering test mode, the status LED will flash
a code representing the last fault. For diagnostic ease at
the thermostat, the alarm relay will also cycle during test
mode. The alarm relay will cycle on and off similar to the
status LED to indicate a code representing the last fault, at
the thermostat. Test mode can be exited by shorting the
test terminals for 3 seconds.
Retry mode:
If the control is attempting a retry of a fault,
the status LED will slow flash (slow flash = one flash
every 2 seconds) to indicate the control is in the process
of retrying.
Field Configuration Options -
Note: In the following
field configuration options, jumper wires should be clipped
ONLY when power is removed from the DXM control.
Water coil low temperature limit setting:
Jumper
3 (JW3-LT1 Low Temp) provides field selection of
temperature limit setting for LT1 of 30°F or 10°F [-1°F or
-12°C] (refrigerant temperature).
Not Clipped = 30°F [-1°C]. Clipped = 10°F [-12°C].
Air coil low temperature limit setting: Jumper 2 (JW2-LT2
Low Temp) provides field selection of temperature limit
setting for LT2 of 30°F or 10°F [-1°F or -12°C] (refrigerant
temperature).
Note: This jumper should only
be clipped under extenuating circumstances,
as recommended by Enertech technical
services.
Not Clipped = 30°F [-1°C].
Clipped = 10°F [-12°C].
Alarm relay setting:
Jumper 4 (JW4-AL2
Dry) provides field selection of the alarm relay
terminal AL2 to be jumpered to 24VAC or to be
a dry contact (no connection).
Not Clipped = AL2 connected to R.
Clipped = AL2 dry contact (no connection).
Low pressure normally open:
Jumper 1 (JW1-
LP norm open) provides field selection for low
pressure input to be normally closed or normally open.
Not Clipped = LP normally closed.
Clipped = LP normally open.
DIP Switches - Note: In the following field
configuration options, DIP switches should only be
changed when power is removed from the DXM
control.
DIP Package #1 (S1)
- DIP Package #1 has 8 switches
and provides the following setup selections:
1.1
- Not Applicable.
On = Enabled. Off = Disabled.
1.2
- Compressor relay staging operation: DIP 1.2
provides selection of compressor relay staging operation.
The compressor relay can be selected to turn on with a
stage 1 or stage 2 call from the thermostat. This is used
with dual stage units (2 compressors where 2 DXM
controls are being used) or with master/subordinate
applications. In master/subordinate applications, each
compressor and fan will stage according to its appropriate
DIP 1.2 setting. If set to stage 2, the compressor will have
a 3 second on-delay before energizing during a Stage 2
demand. Also, if set for stage 2, the alarm relay will NOT
cycle during test mode.
On = Stage 1. Off = Stage 2.
Table 7b: DXM LED And Alarm Relay Operations
