Aerco Benchmark BMK 750 User Manual page 65

Benchmark 750-3000 Boiler Operation, Service, Maintenance Guide - KOREA
SECTION 5 – TROUBLESHOOTING GUIDE
TABLE 5-1: Boiler Troubleshooting Procedures
Fault
Probable Causes
Indication
Interlock jumper not installed or removed.
1.
Energy Management System does not have
2.
INTERLOCK unit enabled.
OPEN
Device proving switch hooked to interlocks is
3.
not closed.
Line and Neutral switched in AC Power Box.
1.
LINE VOLTAGE
OUT OF
Incorrect power supply transformer wiring.
2.
PHASE
1. Incorrect supply gas pressure.
LOW GAS
Defective Low Gas Pressure switch.
2.
PRESSURE
Insufficient water level in system.
1.
Defective water level circuitry.
2.
LOW WATER
LEVEL
Defective water level probe.
3.
MODBUS
Unit not seeing information from Modbus network.
COMMFAULT
OMM-0128_0C
GF-206-K
Corrective Action
Check for a jumper properly installed across the interlock terminals
1.
in the I/O box.
If there are two external wires on these terminals check any Energy
2.
Management system to see if they have the units disabled (a
jumper may be temporarily installed to see if the interlock circuit is
functioning).
Check that proving switch for any device hooked to the interlock
3.
circuit is closing and that the device is operational.
Check hot and neutral in AC Power Box to ensure they are not
1.
reversed.
Check transformer wiring, in AC Power Box, against the power box
2.
transformer wiring diagram to ensure it is wired correctly.
Measure gas pressure upstream of the SSOV Actuator(s) with the
1.
unit firing. Ensure it is above the values in Table 5-1 (BMK 750-
2500) or or above the value calculated in step 4 in section 5.2 (BMK
3000) of the Benchmark 750 – 3000 Boiler Installation and Startup
Guide Guide, OMM-0127 (GF-205-K).
Measure gas pressure at the Low Gas Pressure switch. If it is
2.
greater than 1 inch above the Low Gas Pressure switch setting
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 Boiler
Installation and Startup Guide Guide, OMM-0127 (GF-205-K))
measure continuity across the switch and replace if necessary.
Check system for sufficient water level.
1.
Test water level circuitry using the C-More Controller front panel
2.
LOW WATER TEST and RESET buttons. Replace water level
circuitry if it does not respond.
Check continuity of probe end to the shell, change probe if there is
3.
no continuity.
Check network connections. If fault persists, contact qualified
Service Personnel.
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913
Ph.: 800-526-0288
Page 65 of 146
11/29/2017