Ingersoll-Rand ReliaTel, Manual, Page: 123 / 176

RT-SVD03L-EN 123
• Opening for 3 seconds and closing the main power
disconnect switch,
• By switching the "Mode" switch on the zone sensor
to "OFF" and then to the desired position, or
• Allowing the ignition control module to reset
automatically after one hour.
If the burner trips due to a high temperature limit, the
unit will shut down and initiate a four flash diagnostic.
After the limit cools down and closes, the burner will
again restart. There is no limit to the number of high
limit trips that can occur.
When the RTRM is communicating with the ignition
module (IGN), the MODBUS voltage can be measured
at the 3J5 plug, pins 3 (negative) and 4 (positive). The
voltage will be flashing at approximately 10.7 to 9.6 vdc
at a rate of once every three seconds. If the 3J5 plug is
disconnected, the measured voltage at pins 3 and 4 on
the RTRM will be approximately 10.5 to 11.2 vdc and
will be flashing. Flame current measurements can also
be made at two pins on the ignition module labeled
"FLAME CHECK" located at the bottom of the module.
Flame current can be measured with a DC voltmeter.
One volt dc equals one microamp of flame current
(1vdc = 1mA).
27.5 to 50 tons "high heat" units use two drum and tube
heat exchangers. Two ignition controls work in tandem
to provide heat as required.
Figure 73. ReliaTel ™ ™ hot surface ignition control sequence of operation
1st Stage Call
for Heat
Ignitor
Starts Heating
Combustion
Fan On
60 sec.
Start Trial
for Ignition
1st Stage
Heat On
Start 45 sec
timing for
ID fan
ID fan
starts
Heater goes
to low fire
Heater goes
to 2nd stage
Heating Call
Terminates
Combustion
Fan Off
ID Fan
Continues to
Run for 60 sec.
Indoor
Fan
Shuts Off
If a Call for 2nd
Stage, Heater
Stays on High Fire
Fires on
High Heat
Time will vary
depending on call
for 2nd stage
45 sec.
7 sec.
45 sec.
1 min.
Modulating heat units utilize a variable speed
combustion blower motor that enables the motor to
operate at the necessary speed required to provide the amount of heat required to satisfy the current heating
load of the building.
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