6
6
C.6 Switches & Dials
1. ‘POWER ON/OFF’
This allows you to turn OFF/ON the EMS. This switch
is also used to reset the EMS in case of a lockout. Four
alarms from the heater within less than 5 minutes.
2. ‘SIMULATE PRECIPITATION ON/OFF’
This is normally OFF. To simulate moisture (snow or
rain) you can switch it ON and the EMS receives a
signal the sensor is wet. Used to test and troubleshoot
the EMS.
3. ‘SENSITIVITY’
This knob is used to adjust the sensitivity of the
precipitation sensor. 6 is maximum sensitivity and 1 is
least sensitive. Factory set at 3.5.
4. ‘SNOW-RAIN TEMP’
Adjustable set point, from -12°C to 12°C (10°F to 54°F).
If the ambient temperature is below this set point,
the EMS sees any moisture as snow and will turn the
heater ON. Above this set point it detects rain and
will not turn on the heater.
5. ‘SWITCH WARM TEMP’
This set point is not used with this EMS. This feature is
used only with the intermediate EMS.
6. ‘LOW TEMP CUT OUT’ 5°C to -55°C (41°F to -67°F)
This set point determines the temperature at which the
heater will be turned OFF. Usually set to -35°C (-31°F).
NOTE: Propane gas does not provide adequate vapour pressure
below -40°C/F. By disabling the heater at temperatures
below the set point, alarm shutdown and manual resets
are avoided.
NOTE: Natural gas red heaters or propane tanks with tank
heaters DO NOT require this feature and the set point
can be lowered to the minimum of -55°C (-67°F).
7. ‘DELAY ON’, ‘DELAY OFF’ DIP SWTCHES ON THE
BOARD
These switches are used to set the DELAY ON and
DELAY OFF times for EMS operation. The value of the
time is calculated by adding the binary code value
of the actual switch. Minimum step is one minute.
The values are 1, 2, 4, 8, 16, 32, 64, and 128 and any
combination between, and up to 255 minutes.
Example shown has 5 minutes delay on and 15
minutes delay off.
8. Heaters equipped with the ‘AGGRESSIVE RETRY
OPTION’
If the heater is equipped with the AGGRESSIVE RETRY
OPTION, the EMS will reset the heater up to three
times within 5 minutes and then lock out.
C.7 Status LEDs
Status LED Description
POWER Indicates 12V DC present on the
board
CLOCK Blinking once a second means clock
is working
HEATER ON Heater relay is energized. Heaters
requested to run
SENSOR WET Indicates when the sensor is wet or
simulated wet
DELAYS
Shows Delay Status:
ࢦDark: No delay time active
ࢦLit: Delay time active. Either delay
off or delay on time
–If ‘HEATER ON’ LED is dark -
delay on time
–If ‘HEATER ON’ LED is lit -
delay off time
ࢦBlinking: Delay time reset to zero
RESET Relay to reset ame safety relay.
(Aggressive retry)
AMBIENT Ambient temperature is below
SNOW/RAIN TEMP and sensor is wet
SW WARM
Ambient temperature is below
SWITCH WARM set point (not
available with this EMS)
LOW TEMP
Ambient temperature is below low
temp cut out set point. EMS will turn
the heater off. LED heater on is dark
(heater on relay de-energized)
