Benchmark 750-3000 Operation, Service & Maintenance Guide-Latin America
SECTION 5 – TROUBLESHOOTING GUIDE
OMM-0132A
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
Page
65
of
162
GF-206-LA-LA
Ph.: 800-526-0288
01/02/2018
TABLE 5-1: Boiler Troubleshooting Procedures
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 gas pressure upstream of the SSOV Actuator(s) with the
unit firing. Ensure it is above the values in Table 5-1 (BMK 750-
2500) or above the value calculated in step 4 in section 5.2.2 (BMK
3000)of the
Benchmark 750 – 3000 Installation and Startup Guide
,
OMM-0131 (GF-205-LA).
2.
Measure gas pressure at the Low Gas Pressure switch. If it is
greater than
1 inch above
the Low Gas Pressure switch setting
(see Table 5-1 (BMK 750-2500) or above the value calculated in
step 4 in section 5.2.2 (BMK 3000) in section 5.2 of the
Benchmark
750 – 3000 Installation and Startup Guide
, OMM-0131 (GF-205-LA))
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 C-More Controller 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.
