THERMO 2000 MINI BTH - Electrical Supply of External Accessories; Thermostat(S) and Pump(S) Connections

Electric boilers MINI BTH Installation & Operating Manual (Revision: May 2015), 9
3.5.2 Electrical supply of External
accessories
The total 120vac consumption of the boiler and
external accessories must not exceed 5A.
The maximum electrical consumption of 24vac
external accessories connected to R&C
terminals must not exceed 30Va.
3.5. Thermostat(s) and pump(s)
connections
Thermostat: Use a low voltage 24Vac
thermostat designed for central heating system
(do not use a 240Vac thermostat designed for
electric baseboards).
Some thermostats are equipped with a
temperature sensor for radiant floor application.
The purpose of the thermostat is to control the
operation of the circulating pump. When the
boiler water will drop, the electric heating
element will come on.
Heating systems equipped with one
thermostat and one pump:
With an 18 gauge cable, connect the room
thermostat directly to the following boiler
terminals.
Two wire thermostat: Terminals “R” and “W”
Three wire thermostat: Terminals “C”, “R” and
“W”
Using 14 gauge wires to connect the circulating
pump directly on terminals “P1-P2” (120vac)
Multiple pumps zoning applications:
Components shall be connected in such a way
that when a thermostat is generating a heat
demand, only the corresponding pump will
operate.
To do so, you will need relays as illustrated
below.
Boiler terminals P1-P2 and C-R-W will not be
used.
Diagramme électrique/ Wiring diagram
Raccordement de multiples circulateurs/ Wiring for multiple circulators
Thermostat
Zone 1
T
T
12
3
4
Relais/Relay
RA89A
T
T
1
2
Relais/Relay
RA89A
L2L1
Thermostat
Zone 2
Circulateur/
circulator
Zone 1
Circulateur/
circulator
Zone 2
electrical service
120Vac
Note: Des relais multipompes sont aussi disponibles de la
compagnie Taco (série SR500) ou de Honeywell R8888 pour
faciliter les raccordements dans un seul boîtier / Multiple switching
relays are also available from Taco (series 500) ou from Honeywell
R8888 to symplify the connections on a single box
3
4
Figure 5 : Zoning with multiple pumps