Kaisai KMK-60RY1, Service Manual

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M thermal Split
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4.4 E2 Troubleshooting
Digital display output 4.4.1
Description 4.4.2

Communication error between hydronic box and user interface.

Split stops running.

Error code is displayed on hydronic box main PCB and user
interface.
Possible causes 4.4.3

Communication wires between hydronic box and user interface not connected properly.

Communication wiring X Y E terminals misconnected.

Loosened wiring within electric control box.

Interference from high voltage wires or other sources of electromagnetic radiation.

Damaged main PCB or electric control box communication terminals block.
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Procedure 4.4.4
E2
Communication wires X Y E have short
circuited, disconnected or are
misconnected
1
Yes
Reconnect the communication wires
No
Communication wires X Y E are not
connected in a daisy chain
Yes
Connect the communication wires in a
daisy chain
No
Wires between hydronic box main PCB
and electric control box communication
terminals block are loose
Yes
Ensure the wires are connected properly
No
Interference from high voltage (220V or
higher) wires
Yes
Ensure the communication wires and
high voltage wires are separated
No
Communication wires are close to a
source of electromagnetic radiation such
as transformer or strong fluorescent lamp
Yes
Remove the source of interference, or
add additional shielding to the
communication wires
No
Replacing electric control box
communication terminals block resolves
the error
No
Replace hydronic box main PCB
Notes:
1. Measure the resistance among X, Y and E. The normal resistance between P and Q is 120Ω, between P and E is infinite, between Y and E is infinite.
Communication wiring has polarity. Ensure that the X wire is connected to X terminals and the Y wire is connected to Y terminals.
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