Installation / Operation Instruction Manual

Table Of Contents
Page 113
10.F Transmitters
This unit utilizes a pair of pressure transmitters to
determine that the pressure drop across the combustion
air/ue gas side of the system is within acceptable
bounds for proper operation. If during operation the
di󰀨erential pressure across the system exceeds a
predetermined value at a given ring rate, the system
will shut down and a “Burner An Pressure Error” will
be displayed. The pressure transmitters measure the
di󰀨erential pressure from the inlet lter box to the outlet
of the heat exchanger. Figure 44 on page 113 shows
the allowable di󰀨erential versus the ring rate for each
size boiler. This condition may arise due to excessive
duct lengths, blockage of the inlet or outlet ducts, dirty
inlet lter or fouling of the heat exchanger air side.
The pressure transmitter values during pre-purge may
also prevent the boiler from ring. If the di󰀨erential
pressure exceeds 3.5 inches of water column, the
system will enter a lockout condition and a “Burner
Pressure Error” will be displayed.
See Figure 44 on page 113
Figure 44. Maximum System Di󰀨erential Pressure VS Firing Rate
Firing Rate (%)
Maximum System Pressure Drop (inches water column)