Eco-King HWB-299, Installation And Service Manual

Page: 63 / 124

E93.1801EN171 HWB installation manual 63
Explanation of the low voltage connections.
1-2 DO NOT USE
Do not connect wires to these terminals
3-4 SYSTEM SENSOR
If a low loss header is used, this sensor measures the Outlet temperature at the system side. The sensor must
be mounted on the supply pipe or in a sensor well at the system side, close to the low loss header.
NOTICE: This sensor (see
§ 7.21) must be used when water heaters are cascaded with the internal cascade
manager.
PARAMETER: water heater parameter 122, see: 11.9 "programmable in- and outputs"
5-6 DHW SENSOR
When an indirect hot water tank is installed, the DHW mode must be set to 1 or 2. When the DHW mode is set
to 1, a sensor can be connected. This sensor should be mounted
in a well in the tank
. The water heater will
now modulate towards the hot water setpoint. When the DHW mode is set to 2, an aquastat can be connected.
When the set temperature is reached, the aquastat will switch off and the water heater will stop serving hot
water.
7-8-9 MODBUS
Connections for a MODBUS communication signal.
7 = ground, 8 = A, 9 = B (A detailed Modbus bulletin is available at your supplier on request)
10-11 AL-BUS DEPENDING
Cascade connections for the dependent water heaters, must be parallel linked together.
NOTICE: link all connections 10 to 10 and all connections 11 to 11, do not mix these.
Link connections 10 of the dependent water heaters to 20 of the managing water heater, and connections 11
of the dependent water heaters to 21 of the managing water heater.
12-13 DO NOT USE
Do not connect wires to these terminals
14-15 DO NOT USE
Do not connect wires to these terminals
16-17 DHW - FLOW SWITCH
For DHW_Mode 3 a flow switch can be connected. If a water flow is present, the switch closes, and the DHW
pump is started. The temperature of the DHW is set with DHW_Setpoint.
PARAMETER: water heater parameter 117, see: 11.9 "programmable in- and outputs"
18-19 DO NOT USE
Do not connect wires to these terminals
20-21 AL-BUS MANAGING
Cascade connection for the managing water heater.
Link connection 20 of the managing water heater to connections 10 of the depending water heaters, and con-
nection 21 of the managing water heater to connections 11 of the depending water heaters.
22-23 LWCO EXTERN
To be used for an extra external Low Water Cut Off. The water heater goes into a lockout when this contact
opens
24-25 GAS PRESSURE SWITCH
To be used for an extra external gas pressure switch. The water heater goes into a lockout when this contact
opens PARAMETER: water heater parameter 118, see: 11.9 "programmable in- and outputs"
26-27 SAFETY SWITCH 1
To be used for an extra external safety switch. The water heater goes into a lockout when this contact opens
28-29 SAFETY SWITCH 2
To be used for an extra external safety switch. The water heater goes into a lockout when this contact opens