Watts AERCO Benchmark 2.0LN, Operating & Maintenance Instructions

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SAFETY DEVICE TESTING
6-3
6.6.1 REMOTE INTERLOCK
1. Remove the cover from the I/O Box and
locate the REMOTE INTL’K IN terminals.
2. Start the unit in manual mode and fire at
25% to 30% firing rate.
3. If there is a jumper across the REMOTE
INTL’K IN terminals, remove one side of the
jumper. If the interlock is being controlled by
an external device, either open the interlock
via the external device or disconnect one of
the wires leading to the external device.
4. The unit should shut down and display
INTERLOCK OPEN.
5. Once the interlock connection is recon-
nected, the INTERLOCK OPEN message
should automatically clear and the unit
should resume running.
6.6.2 DELAYED INTERLOCK
1. Remove the cover from the I/O Box and
locate the DELAYED INTL’K IN terminals.
2. Start the unit in manual mode and fire at a
25% to 30% firing rate.
3. If there is a jumper across the DELAYED
INTL’K IN terminals, remove one side of the
jumper. If the interlock is connected to a
proving switch of an external device,
disconnect one of the wires leading to the
proving switch.
4. The unit should shut down and display
DELAYED INTERLOCK OPEN. The
FAULT LED should be flashing.
5. Once the interlock connection is recon-
nected, depress the CLEAR button. The
unit should start.
6.7 FLAME FAULT TEST
1. Place the ON/OFF switch in the OFF posi-
tion.
2. Place the unit in the Manual Mode and set
the firing rate between 25% and 30%.
3. Close the manual gas valve located
between the SSOV and the Air/Fuel Valve
(see Fig. 6.3) and the 1/4” ball valve
downstream of the SSOV.
Figure 6.3
Manual Gas Shut-Off Valve Location
4. Place the ON/OFF switch in the ON position
to start the unit.
5. The unit should shut down after reaching the
Ignition cycle and display FLAME LOSS
DURING IGN.
6. Open the valves previously closed in step 3
and depress the
CLEAR
button.
7. Restart the unit and allow it to prove flame.
8. Once flame is proven, close the manual gas
valve located between the safety shut-off
valve and the differential regulator.
9. The unit should shut down and display
FLAME LOSS DURING RUN
.
10. Open the valve previously closed in step 8
and depress the CLEAR button. The unit
should restart and fire.
6.8 AIR FLOW FAULT TEST
1. Start the unit in manual mode and set the
fire rate between 25% and 30%.
2. Once the unit has proved flame, remove
either wire #154 or #155 from the blower
proof switch (see Fig. 6.4) located on the
air/fuel valve.
3. The unit should shut down and display
AIRFLOW FAULT DURING RUN .
4. Replace the wire previously removed from
the blower-proof switch and depress the
CLEAR button. The unit should restart.
DIFFERENTIAL GAS
PRESSURE REGULATOR
MANUAL GAS
SHUT-OFF VALVE