EB-NB Installation Manual

12/28/2018 29 BI804
Faulty sensor default – the OLED display indicates a sensor issue, but the boiler continues to function
based upon a fixed default temperature within the logic.
 RT sensor – no default, this is not critical
 OT sensor – this is only active when outdoor sensor connected during power-up. If faulty,
internal logic sets OT to 0° F (-18° C), boiler should be operating at full output and probably all
stages on
 ST sensor – Internal logic sets ST to 50° F (10° C), all stages are probably on because this is
significantly well below set point
Alarm, freeze – the ST sensor is sensing a value less than 45° F (7° C).
Door switch – this is at the main unit top inside flange and activates when the dead front main unit inside
panel is removed.
Alarm voltage interface – this chart can help check sensor output or wire connections.
Non-Alarm Active Alarm
Pulses Name J1- Port J1 Port
1 Auto Reset HL-2 4 – 24VAC 19 – 5V 4 – 0V 19 – 0V
2 Field added device 7 – 24VDC 18 – 5V 7 – <2VDC 18 – 0V
3 LWCO 2 – 0VAC 16 – 0V 2 – 120VAC 16-5V
4 Option Switch 1 – 120VAC 15 – 5V 1 – 0VAC 15 – 0V
5 Man Reset HL-1 3 – 0VAC 17 – 5V 3 – 120VAC 17 – 0V
Main unit staging CB’s, staging contactors, power source electric element wiring – this should be
straightforward from the attached wiring schematic. As stated above, the common or neutral for all
contactors is via TB1-4 and the “door switch” neutral wire. The L1 side of each contactor coil is from
TB1-2, through the manual reset limit (TB1-3), and through each stage pilot relay at the Sequencer board.
Sequencer, Electro – this rotating relay output board receives 16-bit binary information from the control
module. This 16-bit binary code is on 4 wires, J3-1 through 4.
 Bit 0 is considered no stages on.
 Bits 1 through 15 represent the 15 stages. This means when the sequencer receives a new bit
code it steps in or out to that specific stage. During transition (staging up or staging down going
to the next stage number) the change in stage code number is not recognized or examined.
 Time between stage-up is 4 seconds each, time between stage-down is 2 seconds each.
 An SYS-ON signal or wire (J3-8) is the external “turn on/turn off” function.
 The output pilot duty relay contacts associated with each connector are all commoned from J2-10
and J3-8. As the staging relays pull in and out this voltage (typical 120 for contactor coil) is fed
to each of the staging contactors.
 At J3-6 24VDC must be there at all times. J3-5 is common or reference.
 Note – the vessel top automatic reset limit (HL-2) is in series with the SYS-ON wire thus it
interrupts the Sequencer, but the Sequencer times its stage-down and stage-up function.
STAGE CODE: Should there be a scenario where you’d like to have the boiler force a certain amount of
stages on (calculation GPM for example), this is where you would indicate the amount of stages you’d
like activated.
FORCE STAGES: Should there be a scenario where you’d like to have the boiler force a certain amount
of stages on (calculation GPM for example), this is where you would active this sequence. Once “YES”
has been selected, the amount of stages selected in the above description (STAGE CODE) will be
activated.
 To exit this operation, “NO” must be selected.