Benchmark 750/1000 Boiler Installation, Operation & Maintenance Manual
CHAPTER 6 – SAFETY DEVICE TESTING
Page
84
of
192
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
OMM-0082_0J
05/21/2014
Ph.: 800-526-0288
GF-130
6.8 AIR FLOW FAULT TESTS
These tests check the operation of the Blower Proof Switch and Blocked Inlet Switch shown in
Figure 6-3.
6.8.1 Blower Proof Switch Test
Blower Proof Switch
Test
1. Disable the blower output drive voltage as follows:
a) Press the
MENU
key until
CONFIGURATION MENU
is displayed.
b)
Press the ▲ arrow key until the
ANALOG OUTPUT
function is displayed, then
press the
CHANGE
key.
c)
Press the ▼ arrow key until
OFF
is displayed, then press the
ENTER
key.
2. Start the unit in the Manual Mode at a valve position between 25% and 30%.
3. The unit should shut down and lockout, showing AIRFLOW FAULT DURING PURGE in
the display.
4. The unit should perform one
IGNITION RETRY
cycle and then shut down, since the
blower is disabled. The unit will then display
AIRFLOW FAULT DURING PURGE.
5. Re-enable the blower output drive voltage by performing the following steps:
a) Press the
MENU
key until
CONFIGURATION MENU
is displayed.
b) Press the
▲ arrow key until the
ANALOG OUTPUT
function is displayed, then
press the
CHANGE
key.
c)
Press the ▲ arrow key until
VALVE POSITION 0-10V
is displayed, then press the
ENTER
key.
d) Press the
CLEAR
button to clear the airflow fault.
6. Once the unit has proved flame, turn off the blower again by going to the Configuration
Menu,
Analog Output
menu item and select
OFF
.
7. The Blower Proof Switch will open and the blower should stop. The unit should shut down
and display
AIRFLOW FAULT DURING RUN
.
8. Go to the Configuration Menu,
Analog Output
item and select
VALVE POSITION 0-10v
.
6.8.2 Blocked Inlet Switch Test
This test will be run in simulated fire mode, with the Blocked Inlet Switch isolated from the rest
of the control circuitry.
Blocked Inlet Switch
Test
1. Turn off the main ON/OFF switch on the front of the Control Panel.
2. For units that get combustion air from a Combustion Air Duct, remove that duct, located
on the rear panel of the boiler (see Figure 6.4, below). For units that have an air filter in
place of a Combustion Air Duct (not shown), remove the air filter.