4
Unit Installation
Notes:
①
The two-way valve is very important to prevent dew condensation on the floor and radiator while cooling
mode;
②
Type of thermostat and specification should be complied with installation of this manual;
③
The by-pass valve must be installed to secure enough water flow rate, and should be installed at the
collector.
CASE 2: Connection between the Electric Heater and the Main Unit
Two groups of electric heaters are available, as well as control terminals for two groups of auxiliary electric
heaters. These two groups of electric heaters can be activated at the same time. When only one group of the
electric heater is installed, please follow the wiring of any group of the diagram shown below.
(1) See the following statement for installation of two groups of auxiliary electric heaters, including wiring of
the AC contactor, the thermostat and the tank-type electric heater.
◆
Wiring of the AC Contactor
L1, L2 and L3 are three-phase input terminals. T1, T2 and T3 are three-phase output terminals. A1 and A2
are terminals of input and output signals which are used to control the AC contactors. NO and NC are normally
open and closed terminals of the AC contactors.
The tank-type electric heater and AC contacts should be selected according to the selection instructions
and the thermostat and its upper limit should be decided by the protection function of the electric heater.
In order to ensure product quality and service life, it is unallowable to do wiring directly at the main board
by the user themselves to prevent the main board from being damaged. The AC contactor control signal input
terminal X17 (AC contactor 1) and X18 (AC contactor 2) of the main board AP1 should be connected to terminal
7 and terminal 8 of the electric box. The single pins of terminal CN26 (AC contactor 1) and CN27 (AC contactor 2)
should be connected to terminal 35 and 36 of the electric box. Besides, other two pins of CN 26 and CN27 both
should be connected to XT2 (see the diagram below for more details).
Only qualified cables are allowed and see the table below for the corresponding wiring terminals.
No.
Wiring Terminal
AC Contactor 1
7—A1
35—2T1
AC Contactor 2
8—A1
36—2T2
◆
Wiring of the Thermostat
The proper limit of the thermostat should be selected based on the protection function of the electric heater.
Firstly, short-circuit the ON/OFF control signal output terminals of AC contactor 1 and AC contactor 2, and
then connect them with the thermostat in series. Do not let the temperature of the external wall of the tank-type
electric heater too high (see the diagram below for more details). After that, apply heat-conducting paste on the
sensing probe and then insert it to the sensing hole to sense the temperature of the external wall of the tank-
type electric heater.
◆
Wiring of the Tank-type Electric Tank
The tank-type electric heater with proper power output should be used and the heating pipe should be
installed at the water inlet side of the unit.
Three-phase wiring for the electric heater should be supplied by the user themselves. A new electric box is
recommended to be used. See the diagram below for more details.
When protection function of the thermostat is required, the sensing probe applied with heat-conducting
paste should be inserted into the sensing hole after wiring of the electric heater has been finished.
