Bosch ZWB28-3A - Electrical Connections in the Junction Box; (120 Vac); Mounting Rails for Junction Box; Connecting an External Heating Zone Pump or DHW Recirculation Pump

Making the electrical connections | 55
6 720 643 068 (2011/06)Copyright (optional information)
Connecting Third party room thermostats or zone
controls
A voltage free (dry contact) third party room thermostat or
heat demand from a relay panel can be used to send an
ON/OFF signal to the appliance.
Fig. 43 Electrical wiring third party room thermostat or
zone control
To communicate a heat demand the third party room
thermostat or zone control must connect pins 2 and 4.
6.3 Electrical connections in the junction
box (120 VAC)
6.3.1 Mounting rails for junction box
B Hold the rail against the appliance from below (step 1)
and fasten with the screws from the outside or inside
(step 2).
B Loosen junction box from the rail (step 3).
Fig. 44 Mounting rails for junction box
6.3.2 Connecting an external heating zone pump or
DHW recirculation pump
Without accessories the appliance offers the connection
of one heating zone pump, one circulator of an unmixed
heating circuit, or one DHW recirculation pump.
The pump used must have the following connection
values: 120 VAC, max. 2 A.
B Route cable from pump to appliance.
B Insert cable into the junction box as shown in Fig. 46.
B Connect cable to the black plug according to Fig. 45.
Fig. 45 Attach plug (external pump)
1 L (120 VAC, 60 Hz)
2 PE (GND, Ground)
3 N (Neutral)
4 Black plug (in the junction box upon delivery)
B Connect black plugs and insert grommet until stop.
Fig. 46 Cable connected (external pump)
B Use service function 5.E, to set connection to 01 (DHW
recirculation pump) (Æ page 71)
-or-
B Use service function 5.E to set connection to 02
(external heating zone pump in an unmixed heating
circuit) (Æ page 71).
-or-
B Use service function 5.E to set connection to 03
(external heating pump) (Æ page 71).
6 720 641 933-70.1O
B
B
4
2
1
F
A
LS NS
LP
NP
9
8
7
1
2
ϑ
6 720 641 933-42.1O
1
3
2
2
The DHW recirculation pump is controlled by
the Bosch FW 200.
1
2
3
4
6 720 641 933-41.1O
L PE N
white
Mains
120V/60Hz
L PE N
red
Storage
tank pump
L PE N
black
CH pump
for mixed heating
8 737 701 503
I III III III
6 720 641 933-40.1O