AERCO BMK 3.0 LN Dual Fuel June 2010 - Manual (Page 54)

SAFETY DEVICE TESTING
6. Once the unit has proved flame, turn off the
blower 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 Fire Rate 0-10v.
9. Press the CLEAR button. The unit should
restart.
10. Next, check the Blocked Inlet Switch by first
noting the current position of the Iris Air
Damper and then closing the Damper to
position 8.
11. .The unit should shut down and again
display AIRFLOW FAULT DURING RUN.
12. Return the Iris Air Damper to its previous
setting.
13. Press the CLEAR button. The unit should
restart.
6.11 SSOV PROOF OF CLOSURE
SWITCH
This test can be performed when the unit is set
up to run on either natural gas or proane fuel.
Downstream SSOVs #1 (natural gas) and #3
(propane) shown in Figure 6-1 contain the proof
of closure switches. The proof of closure switch
circuit is checked as follows:
1. Set the unit’s ON/OFF switch to the OFF
position.
2. Place the unit in Manual Mode and set the
valve position between 25% and 30%
3. Refer to Figure 6-1 and locate downstream
SSOV #1(natural gas).
4. Remove the cover from SSOV #1 by
loosening the screw shown in Figure 6-4. Lift
off the cover to access the terminal wiring
connections.
5. Disconnect wire #148 from SSOV #1 to
“open” the proof of closure switch circuit.
When wire #148 is disconnected, it opens
the proof of closure switch circuit for both
the natural gas and propane downstream
SSOVs.
6. The unit should fault and display SSOV
SWITCH OPEN.
7. Replace wire #148 and press the CLEAR
button.
8. Set the ON/OFF switch to ON to start the
unit.
9. Remove the wire again when the unit
reaches the purge cycle and PURGING is
displayed.
10. The unit should shut down and display
SSOV FAULT DURING PURGE.
11. Replace the wire on SSOV #1 and press the
CLEAR button. The unit should restart.
ACTUATOR
COVER
SCREW
SSOV #1
ACTUATOR
COVER
Figure 6-4
SSOV #1 Actuator Cover Location
6.12 PURGE SWITCH OPEN DURING
PURGE
The Purge Switch (and Ignition Switch) is
located on the Air/Fuel Valve. To check the
switch, proceed as follows:
1. Set the unit’s ON/OFF switch to the OFF
position. Place the unit in manual mode and
set the fire rate between 25% and 30%.
2. Remove the Air/Fuel Valve cover by rotating
the cover counterclockwise to unlock it and
then lift up (see Figure 6-5).
3. Remove one of the two wires (#171 or #172)
from the Purge Switch (Figure 6-6).
4. Initiate a unit start sequence.
6-6