15. External wiring of UHR-820 type control board
15.1 Wiring description
15.1.1 Communication port (MB312-508 type 4-wire 5.08mm terminal)
Connect the same terminals of GND, A, B terminals of the wired controller and the module control board in
parallel and only connect the +12V on control board of the master module (address is 0) to the same
terminal (+12V) on the wired controller.
15.1.2 Temp. sensor port (VH-2 type 9-wire 3.96mm socket)
Totally 8 pieces of temp. sensors, herein, 2 pieces of compressor discharging temp. sensor are specially
high temp. sensor (model: DTN-G514H8A-ACU104H 50KΩ B=4450); the others are normal temperature
sensors (model: DTN-C502H3T-ACU123B 5KΩ B=3470). One end of the sensors is connected to the
relative port, the other end is to the COM port.
15.1.3 Protection signal port (VH-2 type 10-wire 3.96mm socket)
Totally 9 ways of protection signals, which are ON/OFF signal, normally, they are connected, while in failure,
they are disconnected. One end is to the COM port, while the other end is to the relative port.
15.1.4 Relay output port (11 pieces of 6.35*0.8mm lug)
Port marked with AC-N must be connected to the neutral wire of power supply circuit (allowable max.
current is 30A), the others are respectively to N terminal of the AC contactor.
15.1.5 AC power supply input port of control board (VH-2 type 3-wire 3.96mm socket)
Input AC voltage 220V, current ≯0.1A. Pay attention that the phase wire and the neutral wire cannot be
fixed improperly, and the power supply of the phase wires and the contactor should be the same. Otherwise,
the anti-interference of controller and the relay life will be affected.
15.1.6 Power supply transformer port (VH-2 type 6-wire 3.96mm socket)
The two ports marked with AC-220V are connected to the primary winding of transformer; The ports marked
with AC-6V and AC-16V are connected to the secondary winding of transformer.