Aerco BENCHMARK 2500DF User Manual page 111

Benchmark 2500DF-3000DF Installation, Operation & Maintenance Manual
FAULT INDICATION
1. Interlock jumper not installed or
INTERLOCK
OPEN
2. Energy Management System does
3. Device proving switch hooked to
1. Line and Neutral switched in AC
LINE VOLTAGE
OUT OF PHASE
2. Incorrect power supply transformer
1. Incorrect supply gas pressure.
LOW GAS
PRESSURE
2. Defective Low Pressure Gas Switch
1. Insufficient water level in system
LOW WATER
2. Defective water level circuitry.
LEVEL
3. Defective water level probe.
Unit
MODBUS COMMFAULT
Modbus network
OMM-0099_0A
GF-145
CHAPTER 8 – TROUBLESHOOTING GUIDE
TABLE 8-1: BOILER TROUBLESHOOTING – Continued
PROBABLE CAUSES
removed
not have unit enabled.
interlocks is not closed.
Power Box.
wiring.
not seeing information
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913
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.
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
1. Measure gas pressure upstream of the SSOV Actuator(s) with the unit
firing. Ensure the following values as follows:
2. For Natural Gas gas-trains, ensure it is between 8.0" W.C. and 14" W.C.
For Propane Gas gas-trains, ensure it is between 4.0" W.C. and 14" W.C.
(see section. 2.8.1).
3. Measure gas pressure at the low gas pressure switch. If greater than the
following values, measure continuity across the switch and replace if
necessary:
a) BMK3000 DF = If it is greater than 2.6" W.C. for Propane Gas or
greater than 7.5" W.C. for Natural Gas.
b) BMK2500 DF = If it is greater than 3.6" W.C. for Propane Gas or
greater than 7.5" W.C. for Natural Gas.
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.
from Check network connections. If fault persists, contact qualified Service
Personnel.
Ph.: 800-526-0288
CORRECTIVE ACTION
Page 111 of 234
PR1: 05/21/2014