11
SK Models IOM
Enertech Global
SECTION 6: CONTROLS
Fan Alarm:
When the fan is running in normal operation,
the
fan alarm output is closed (shorted). If the fan alarm
output is open for 30 continuous seconds while the
fan is running, a fan alarm is tripped. The orange
LEDs will flash once per second to indicate a fan
fault and the L terminal is energized.
Maintenance:
Coil Care:
Keep the unit free of loose snow, foliage, grass
clippings, leaves, paper, and any other material
which could restrict the proper air flow in and out
of the unit. The coil may be vacuumed to remove
any debris from between the fins. However, do not
knock ice off the unit’s coil surface following an ice
or severe snowstorm. The blows could mash the
coil fins shut (blocking air passage), or break the
tubing allowing fluid to escape.
If the coil becomes excessively dirty, turn the main
disconnect switch to “OFF” and wash the coil with
a garden hose. Avoid getting water into the control
box. Remove any dirt and debris from the fan
plenum. Access to the fan plenum is possible by
removing the top of the unit and then the top panel
of the plenum.
PUMP
R_1
R_2
C_2 C_1
C
C
G
C
C
G
1
FA
N
C
R
C
C
I
N
O
1
L
FS1
FAN2
FAN1
O
FS2
EAT
EWT
OFF
←
GRN
ORG
RED
YLW
STATUS
1
2
3
4
Heat
Pump
Fluid
Cooler
To Loop Field
From Loop Field
GREEN
ORANGE
RED
YELLOW
STATUS
ON
FLASH
ON
FLASH
ON
ON
FLASH
ON
FLASH
X
X
X
ON
FLASH
X
X
X
SLOW FLASH
FLASH
X
X
X
FAST FLASH
FLASH
X
SLOW FLASH
X
X
FLASH
X = DIP SWITCH OPTION SELECTED
1
2
3
4
2
OPTION #1 (LOOP PUMP)
OFF
OFF
OFF
OPTION #2 (LOOP PUMP)
ON
OFF
OFF
OPTION #3 ( LOOP PUMP)
OFF
ON
OFF
OPTION #4 (FLOW SWITCH)
ON
ON
OFF
OPTION #1 (LOOP PUMP)
OFF
OFF
ON
OPTION #2 (LOOP PUMP)
ON
OFF
ON
OPTION #3 ( LOOP PUMP)
OFF
ON
ON
OPTION #4 (FLOW SWITCH)
ON
ON
ON
NOTES:
2. DIP SWITCH 4 HAS NO FUNCTION.
1. DIP SWITCH 3 DETERMINES THE FLUID TYPE. IF PURE WATER IS BEING USED, DIP SWITCH 3 SHOULD BE OFF, AND
IF AN ANTIFREEZE SOLUTION IS BEING USED, DIP SWITCH 3 SHOULD BE ON.
MODE OF OPERATION
REV B. 5/31/17
DIP SWITCH OPTION #1 SELECTED
DIP SWITCH OPTION #2 SELECTED
DIP SWITCH OPTION #3 SELECTED
DIP SWITCH OPTION #4 SELECTED
EAT SENSOR FAULTY
EWT SENSOR FAULTY
BOTH EAT AND EWT SENSORS FAULTY
COOL LOOP W/O 'CC' AND 'O' CALL
FROM HEAT PUMP
COMBINATION OF 1 AND 2
COOL LOOP W/O 'CC' AND 'O' CALL
FROM HEAT PUMP
DIP SWITCHES
1
DESCRIPTION OF OPERATION
HEAT OR COOL LOOP UTILIZING 'CC'
AND 'O' CALL FROM HEAT PUMP
FAN FAULT
CONTROL BOARD LED IDENTIFICATION
HEAT OR COOL LOOP UTILIZING 'CC'
AND 'O' CALL FROM HEAT PUMP
COOL LOOP W/O 'CC' AND 'O' CALL
FROM HEAT PUMP
COMBINATION OF 1 AND 2
COOL LOOP W/O 'CC' AND 'O' CALL
FROM HEAT PUMP
DIP SWITCH SELECTION
CONDITION
LED Identification and DIP Switch Selection
Temperature Sensor Operating Range:
Sensor Name
Temperature
Monitored
Range (°F)
EAT
Ambient Air
-40 – 140
EWT
Fluid Temp
-15 – 120
Temperature vs. Resistance Characteristics:
Temp. (°F)
Rst. (KΩ)
Temp. (°F)
Rst. (KΩ)
10
46.95
130
3.60
15
41.39
200
1.16
20
36.50
220
0.87
30
28.61
250
0.59
77
10.00
257
0.54
Control Board Layout