AERCO BMK 1.5 LN October 2012 - Manual (Page 73)

CHAPTER 6
SAFETY DEVICE TESTING
PR1: 10/18//12 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 Page 73 of 166
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
Installation, Operation and Maintenance Manual
Once the adjustable over-temperature switch setting is approximately at, or just below, 6.
the actual outlet water temperature, the unit should shut down. The FAULT indicator
should start flashing and a HIGH WATER TEMP SWITCH OPEN fault message should
be displayed. It should not be possible to restart the unit.
Reset the adjustable over-temperature switch to its original setting. 7.
The unit should start once the adjustable temperature limit switch setting is above the 8.
actual outlet water temperature.
6.6 INTERLOCK TESTS
The unit is equipped with two interlock circuits called the Remote Interlock and Delayed
Interlock. Terminal connections for these circuits are located in the I/O Box (Figure 2-9) and are
labeled REMOTE INTL’K IN and DELAYED INTL’K IN. These circuits can shut down the unit in
the event that an interlock is opened. These interlocks are shipped from the factory jumpered
(closed). However, each of these interlocks may be utilized in the field as a remote stop and
start, an emergency cut-off, or to prove that a device such as a pump, gas booster, or louver is
operational.
6.6.1 REMOTE INTERLOCK
Remove the cover from the I/O Box and locate the REMOTE INTL’K IN terminals. 1.
Start the unit in the Manual Mode and set the valve position between 25% and 30%. 2.
If there is a jumper across the REMOTE INTL’K IN terminals, remove one side of the 3.
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.
The unit should shut down and display INTERLOCK OPEN. 4.
Once the interlock connection is reconnected, the INTERLOCK OPEN message should 5.
automatically clear and the unit should restart.
6.6.2 DELAYED INTERLOCK
Remove the cover from the I/O Box and locate the DELAYED INTL’K IN terminals. 1.
Start the unit in the Manual Mode at a valve position between 25% and 30%. 2.
If there is a jumper across the DELAYED INTL’K IN terminals, remove one side of the 3.
jumper. If the interlock is connected to a proving switch of an external device,
disconnect one of the wires leading to the proving switch.
The unit should shut down and display a DELAYED INTERLOCK OPEN fault message. 4.
The FAULT LED should be flashing.
Reconnect the wire or jumper removed in step 3 to restore the interlock. 5.
Press the CLEAR button to reset the fault 6.
The unit should start. 7.
6.7 FLAME FAULT TESTS
Flame faults can occur during ignition or while the unit is already running. To simulate each of
these fault conditions, proceed as follows:
Set the ON/OFF switch to the OFF position. 1.