10
Enertech Global
SK Models IOM
compressor is on (CC call), the pump turns on
and the fan comes on when both of the following
conditions are met:
• Air temperature is at least 40°F for water or
25°F for antifreeze
• Fluid temperature is greater than air
temperature plus a 2°F dead-band (at least 42°F
for water or 27°F for antifreeze)
In loop heating mode (O call is NOT present), when
the compressor is on (CC call), the pump turns on
and the fan comes on when both of the following
conditions are met:
• Air temperature is at least 40°F for water or
25°F for antifreeze
• Fluid temperature is less than air temperature
minus a 2°F deadband (38°F for water or 23°F
for antifreeze)
If the compressor is off and air temperature is
greater than 40°F for water or 25°F for antifreeze,
both the pump and fan are off.
Note: If the air temperature is less than 25°F for
fluid type antifreeze or less than 40°F for fluid type
water, the pump is always on and fan is always off
(freeze protection).
Option 2: Internal Pump, No CC or O:
SW1=ON, SW2=OFF
Only loop cooling is allowed. The fan and pump
come on when both of the following are true:
• Air temperature is at least 40°F for water or
25°F for antifreeze
• Fluid temperature is greater than air
temperature plus a 2°F dead-band (at least 42°F
for water or 27°F for antifreeze)
Note: If the air temperature is less than 25°F for
fluid type antifreeze or less than 40°F for fluid type
water, the pump is always on and fan is always off
(freeze protection).
Option 3: Internal Pump, Combination of Option
1 and Option 2, with CC & O:
SW1=OFF, SW2=ON
When in this mode, CC & O calls from the heat
pump signal to do loop heating or loop cooling
according to the same logic as Option 1. It will also
automatically perform loop cooling according to the
temperature logic described in Option 2.
Loop cooling is active when both of the following
conditions are met:
• Air temperature is at least 40ºF for water or 25ºF
for antifreeze
• Fluid temperature is greater than air
temperature plus a 2°F dead-band (at least 42°F
for water or 27°F for antifreeze)
Loop heating (O call is NOT present), when the
compressor is on (CC call), is active when both of
the following conditions are met:
• Air temperature is at least 40º for water or 25ºF
for antifreeze
• Fluid temperature is less than air temperature
minus a 2°F deadband (38°F for water or 23°F
for antifreeze)
Option 4: No Internal Pump-Flow Switch,
No CC or O:
SW1=ON, SW2=ON
When in this mode, the fluid cooler runs in loop
cooling independently from the heat pump. When
the fluid cooler detects flow from an outside pump,
it will engage the fan according to the following
logic.
Loop cooling is enabled when the following
conditions are met:
• The flow switch is closed
• Air temperature is at least 40°F for water or
25°F for antifreeze
• Fluid temperature is greater than air
temperature, 42°F for water or 27°F for
antifreeze
Faults and Indication
EAT Sensor Out of Range/Bad:
Normal operating range for the sensor is -40°F to
140°F. If the air temperature is out of this range, it
is a fault condition. The Yellow LED comes on to
indicate an air sensor fault and the L terminal is
energized.
EWT Sensor Out of Range/Bad:
Normal operating range for the sensor is -15°F to
120°F. If the fluid temperature is out of this range,
it is a fault condition. The Yellow LED will start
flashing once per second to indicate fluid sensor
fault and L terminal is energized.
Note: If both EAT and EWT sensors are bad, the
Yellow LED will blink faster – four times per second.
SECTION 6: CONTROLS