Electrical Hookup - Electro Industries EB-MX-10 Installation & Operating Instructions Manual

ELECTRICAL HOOKUP

Reference drawing BH511
1. 240 Volt Heating Power – route and install the proper current carrying conductors from service
panel fuse or circuit breaker. See Specification Table and/or product nameplate for ratings. These
models contain built-in circuit breakers and meet the requirement for local disconnect for appliances
greater than 10 kW. Connection is at the circuit breaker terminals. If using single feed method,
single feed bus – order part number 5701.
 Only copper wire is allowed.
 CB1 is highest priority stage.
2. Grounding – copper conductor is required, size per NEC code relating to the current of each feed.
3. Circulating Pump – the two orange wires connected to a relay on the control board represent a
switch closure (10-amp maximum) to operate an external circulating pump motor. Voltage for the
pump must come from a separate source.

The pump is controlled as a direct function of the R and W input.

If this is connected with a standby boiler, generally the assumption is series plumbing with
the single pump. In this case, the R and W function will operate the pump whether in electric
or standby mode.

If a standby boiler installation has parallel plumbing with two pumps, field wiring and
controls will be necessary to properly operate (and typically check valve isolate) the standby
boiler self-contained pump from the system pump controlled by these two terminal screws.
4. Operating Thermostat – two types can be used. Connection is at the control board bottom.

Standard Mechanical – connect to "R" and "W", bottom right. Set thermostat internal heat
anticipator to 0.2.

Floor Sensing Stat – connect to "R" and "W", bottom right. Place slab sensor in the slab.

If needed, can connect thermostat "C" to boiler "C
NOTE: Power robbing/power stealing thermostat – if you have a power robbing or power stealing
thermostat, you must use the resistor included with the thermostat. Place this jumper between boiler
"W" and boiler "C". If resistor is not used, intermittent boiler operation can be expected.
Comment: If zone valve or zone pumps see appropriate sections.
5. Load Management Interrupt Control – this Electro-Boiler series has been pre-wired and designed
for an external utility load management receiver connection. The control board lower left terminal
block marked BLU and BLU/WHT represent the two contact points, extend these wires to the utility
load control device. As shipped, this unit is only equipped for off-peak = N.C. logic. If reversed
logic is required, contact the factory for modification.

Optional – if load management is not used, simply keep the two blue wires shorted.

Optional – if the power company disconnects 240V for load control, contact factory for
drawing BH029 for special wiring requirements.
6. Outdoor Sensor (OT, outdoor reset control configuration EB-MX models only) – the loose OT
sensor bracket/probe needs to sense true outdoor temperature. Mount on an outside wall position that
will represent the most accurate outdoor temperature. If possible shade from direct sun rays.

If you have an EB-MS boiler and would like outdoor reset, order part number WFS25F.
10/27/2016
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BI516