Installation / Operation Instruction Manual

02/04/2021 8 BI810
Ground fault detector – BEB Series boilers are manufactured to utilize either of the two common 3-
phase electrical feeds:
 3-Phase Y, with neutral and ground – the internal wiring configuration of the BEB boiler does not
require a neutral. This unit is manufactured and shipped without ground fault protection. Certain
state and local codes may require the addition of ground fault protection. Be certain to research and
follow these codes.
 3-Phase Delta, no neutral, dedicated service from the transformer with unbonded neutral – a ground
fault protection kit must be added in this instance. The addition of this kit to the BEB brings the boiler
into “NEC Article 250.21, unbonded neutral” compliance. This kit may be installed at our factory
upon your request. In addition to the CSA product certification, this safety control system is approved
by Minnesota, North Dakota, and the South Dakota State Boards of Electricity.
Always verify with a qualified electrician if the system is configured as a 3-phase Delta. If a ground fault
detector for 3-phase Delta is installed on a 3-phase Y system, the ground fault monitor will not allow the
boiler to operate.
Additional Safety Control Options
Remote or boiler room emergency stop switch – a field provided stop switch with a normally closed
contact can be easily wired into TB1-1 and 2 located behind the boiler high voltage safety panel. This is a
120V circuit. Simply remove the factory provided black/yellow jumper between 1 and 2 and connect the
normally closed stop switch. A “Remote” fault will display on the monitor when this circuit opens during
boiler operation.
Additional external low water cutoff – this can also be looped into the TB1-1 and 2 mentioned above.
If the external LWCO has a manual reset function, it will need to be reset at that component.
 Alarm monitor “REMOTE” is the monitor for opening TB1-1 and 2.
External water flow switch – this closed to flow contact can also be added to the TB1-1 and 2 black/yel
jumper loop. Its function will keep all power contactor coils de-energized whenever 1 and 2 are open
(also sets remote fault).
 Another suggestion for hot boiler and continuous pump, use the water flow switch as a contact for
opening the R and W system on switch (see Electrical Installation – Preparation section, bottom
paragraph).
Multiple Boilers, Same System
Piping/pumps – boilers are plumbed in parallel, each flowing equally into a header or primary loop.
Steps need to be taken to make sure there is an evenly divided flow into the header, related to the number
of boilers in parallel. Depending upon pump sizing, the primary loop pumping system could be equal size
pumps at each boiler supply pipe. See Specification Table for required flow through each vessel.
Controlling multiple boilers – the control board has built in multi-boiler control with LEAD/LAG
capability. A contact closure is required across R-W at the designated lead boiler. This heat call will
activate the lead boiler and establish communication to the lag boiler. Internal control board logic will
determine all boiler sequencing functions. Each boiler has its own safety LWCO, HL1, and HL2
temperature limits. This control is limited to two Laars boilers.
If a building energy management system is used, a (0-10VDC) control signal is connected in parallel to
each boiler control board. Special setup is required via the boiler control interface panel.
Dual Boilers/Dual System
Electric/gas combination – when the Laars boiler is used in combination with a fossil fuel boiler, control of
both boilers can be achieved through the Laars boiler control board. The “SB IN /OUT” terminals serve as a
control connection to the fossil fuel boiler “TT” or “RW”.
Utility load control – when a utility receiver is connected to the system as shown on BH801, and control is
initiated during an active heat call, the electric stages are terminated and a switch closure is made on “SB
IN/OUT” connection activating the fossil fuel boiler backup.