Installer Connections; Access To Electrical Connections - Bosch Worcester Greenstar HIU E Installation And Maintenance Instructions Manual

5.3.2

Installer connections

NOTICE: Risk of equipment damage
▶ Only 230V room thermostats or 230V
programmable room thermostats can be used with
the HIU units for external time and temperature
control.
▶ The 230V time and temperature controls must only
be wired to the HIU and not from an external 230V
source.
Mains voltage (power cables) connections side
Connections/
Symbol Function
Limiter thermostat (under-floor safety cut-off)
• Potential free
LR L
230 V feed to external controls modules
230V
• Live output [L]
OUT
L N • Neutral output [N]
• Earth output [
230 V supply to the appliance
230V
• Live output [L]
IN
L N • Neutral output [N]
• Earth output [
Not used
PW2
14 N
230 V feed to external time and temperature
control
120/230 VAC
• Switch live demand input [LR]
LR L N
• Live output [L]
• Neutral output [N]
• Earth output [
Not used
PW1
14 N
Table 7
Low voltage (signal cables) connections side
Connections/
Symbol Function
Not used
BUS
2 1
Sense II connection
EMS • Not polarity sensitive
2 1
Outdoor temperature sensor
• Not polarity sensitive
2 1
Not used
2 1
Table 8
6 720 808 928 (2017/06)
]
]
]
5.3.3

Access to electrical connections:

Control box service position
▶ The control box [1] incorporates a hook on the underside to support
the control unit on the plate heat exchanger top bracket [2] whilst
working in the control unit.
1
2
Fig. 31 Accessing electrical connections
▶ Release the latches [4] using a thin bladed screwdriver. Arrows on
the electrical cover indicate the position where the screw driver must
be inserted to release the catches.
▶ Hinge open the connections cover [3].
▶ Wire any mains voltage equipment (timers, room thermostats etc. in
the appropriately marked connector) within the mains voltage
connection points.
3
4
Fig. 32 Accessing electrical connections
Installation
27