Aerco Benchmark 2000 - Page 109

Benchmark 1500 - 2000 Boilers
CHAPTER 8 – TROUBLESHOOTING GUIDE
OMM-0097_0E AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 Page 109 of 182
GF-142 Ph.: 800-526-0288 10/01/2015
TABLE 8-1: BOILER TROUBLESHOOTING – Continued
FAULT INDICATION PROBABLE CAUSES CORRECTIVE ACTION
INTERLOCK
OPEN
1.
Interlock jumper not installed or
removed.
2. Energy Management System
does not have unit enabled.
3. Device proving switch hooked to
interlocks is not closed.
1.
Check for a jumper properly installed across the interlock terminals in the
I/O box.
2. If there are two external wires on these terminals check any Energy
Management system to see if they have the units disabled (a jumper may
be temporarily installed to see if the interlock circuit is functioning).
3. Check that proving switch for any device hooked to the interlock circuit is
closing and that the device is operational.
LINE VOLTAGE
OUT OF PHASE
1.
Line and Neutral switched in AC
Power Box.
2. Incorrect power supply
transformer wiring.
1.
Check hot and neutral in AC Power Box to ensure they are not reversed.
2. Check transformer wiring, in AC Power Box, against the power box
transformer wiring diagram to ensure it is wired correctly.
LOW GAS
PRESSURE
1.
Incorrect supply gas pressure.
2. Defective Low Gas Pressure
switch.
1.
Measure NATURAL GAS pressure upstream of the SSOV Actuator(s)
with the unit firing. For FM gas trains, ensure it is between 6.0” W.C. and
14” W.C. (1485 and 3487 Pa). For DBB gas trains, ensure it is between
6.5" W.C. and 14” W.C. (1619 and 3487 Pa) (see section 4.3).
2. Measure NATURAL GAS pressure at the Low Gas Pressure switch. If it is
greater than 4.7” W.C. (1171 Pa) for both BMK 1500 and BMK 2000,
measure continuity across the switch and replace if necessary.
LOW WATER
LEVEL
1.
Insufficient water level in system.
2. Defective water level circuitry.
3. Defective water level probe.
1.
Check system for sufficient water level.
2. Test water level circuitry using the Control Box front panel LOW WATER
TEST and RESET buttons. Replace water level circuitry if it does not
respond.
3. Check continuity of probe end to the shell, change probe if there is no
continuity.
MODBUS
COMMFAULT
Unit not seeing information from
Modbus network.
Check network connections. If fault persists, contact qualified Service
Personnel.
PRG SWTCH CLOSED
DURING IGNITION
1.
A/F Valve rotated open to purge
and did not rotate to ignition
position.
1.
Start the unit. The Air/Fuel Valve should rotate to the purge (open)
position, then back to ignition position (towards closed) during the ignition
cycle. If the valve does not rotate back to the ignition position, check the
Air/Fuel Valve calibration. If calibration is okay, the problem may be in the
Air/Fuel Valve or the Control Box. Refer fault to qualified service
personnel.