Schwank P40U Fenwal - Manual (Page 32)

32
P40U-F / P40U-IF I&O Manual
IM101220
RD: MAY 2014
RL: 5A
22. IGNITION CONTROL: MODELS P40U-P, -W (-IP, -IW) - GASLITER MICRO 50N
The MICRO 50N is a microprocessor-based DSI (Direct Spark Ignition) control which continu-
ously monitors the burner to ensure safe operation under all conditions. The MICRO 50N DSI
Control includes specified purge and trial times, multiple ignition attempts, a diagnostic alarm
output, and automatic recycle on soft lockout. The polyurethane encapsulated circuit board is
suitable for damp and wet environments. The MICRO 50N uses electrode flame sensing.
SPECIFICATIONS
Operating Voltage: 24 VAC, 50/60Hz
Power Consumption: 200mA maximum, exclusive of valve/alarm loads
High Voltage: 15kV minimum with 50 pF load
Spark Gap: 0.150 inches +/- 0.050 inches, 3.8 mm +/- 1.2 mm
Spark Rate: 60 sparks per second
Ignition Trials: Three (3)
Prepurge: 30 seconds
Spark Duration: 20 seconds
Inter-purge: 30 seconds
Soft Lockout / Reset: 30 minutes
Gas Valve Output: 2A maximum
Alarm Output: 2A maximum, dependent on optional alarm type
Operating Temperature: -40°F to +185°F (-40°C to +85°C)
Environmental Protection: Polyurethane encapsulated; 500 hour salt spray test to
ASTM 117
Mating Connectors: 6 Pin: MOLEX 08-50-8063 or equivalent
Timing Specifications: All timings are +/- 10%
NORMAL OPERATING SEQUENCE
Power up / Pre-purge
When powered up, the unit performs a series of diagnostic checks to determine if the system is
in working order.
Trial for Ignition
After a 30 second pre-purge, the unit will power the valve solenoid and begin a 20 second trial
for ignition. The spark will be enabled for the first 80% of the trial period and then suppressed
for the last 20% of the trial period to allow the unit to sense weak flame signals.
Run
When a flame is sensed, the unit suppresses the spark and keeps the valve powered. Power is
removed from the unit when the thermostat is satisfied.
ABNORMAL CONDITION OPERATING SEQUENCE
No Flame Established - Soft Lockout Mode (30 minutes)
If a flame is not established during the trial for ignition, the unit will perform an inter-purge and
retrial for ignition. This protocol is followed for three (3) trials. If a flame is not established during
the final ignition attempt, the unit will enter the soft lockout mode, which includes a reset delay
before another normal trial for ignition series begins.
continued ….