Indoor/Outdoor Control Wire Connection Confi Rmation - Panasonic 2WAY Multi Technical & Service Manual

(11) Indoor/outdoor control wire connection confi rmation
Check the control wire connection regardless of whether there is a warning or not. Before performing the check,
turn off the power of all devices (including controllers) that are connected to the indoor/outdoor control wire.
1
Ground fault check
2
Short circuit check
3
Wire break or
disconnection check
4
Shield wire check
5
Others
*1: Terminal resistor is basically "ON (SHORT)" for one unit only, but depending on the installation status can be
set to "ON (SHORT)" for up to 3 units.
● Device ground check
Is earth ground securely obtained?
● If an error is found in the wiring connections, the following check procedure allows you to quickly identify the
location of the error. When performing the check procedure, it is convenient if you have a drawing showing the
layout of devices and wiring routes to refer to.
• In systems that are comprised of multiple wiring systems linked together, you can quickly identify the
location of the error by removing the 'link' and determining whether each individual system is good or not
good. A warning in a certain system does not necessarily mean that the cause of the error is in that system.
Check the indoor/outdoor control wires of all systems, since the abnormality may be in the wiring of a
system other than that where the warning is triggered.
For W MULTI units
Outdoor
Unit
Wire connecting the systems
Outdoor
Unit
Measure the resistance between one end of the indoor/outdoor control
wire and the point of ground screw, as well as the resistance between the
1-1
other operating line end and the point of ground screw. Are both measured
resistance values in MΩ unit (infi nite)?
Because the indoor/outdoor control wire has a ground fault, search for the location of the
1-2
ground fault.
Measure the resistance between the indoor/outdoor control wires on the
terminal board of the outdoor unit.
2-1 The measured resistance value is around 75 to 100Ω?
When setting multiple "ON (SHORT)" to switches with terminal resistor, the
resistance value mentioned above is 1 over number of units. *1
If the wiring has a short circuit, search for the location of the short circuit on the indoor/
outdoor control wire.
2-2
If it is open, check the terminal resistor of outdoor board, and check the wiring from
outdoor board to outdoor terminal board.
Measure the resistance between the indoor/outdoor control wires on the
3-1 boards of all devices that are connected to the control wires.
Any location with measured resistance values in MΩ units (infi nite)?
3-2 Because the wiring has a break, search for the location of the break.
4-1 A shield wire is used as an indoor/outdoor control wire?
4-2 Only one end of the shield wire is grounded?
4-3 Ground only one end of the shield wire.
5-1 Check total wire length and the number of branch connections and connected units.
Outdoor
Unit
Outdoor
Unit
Indoor Indoor
Unit Unit
Indoor Indoor
Unit Unit
V–54
Yes 2-1
No 1-2
Yes 3-1
No 2-2
Yes 3-2
No 4-1
Yes 4-2
No 5-1
Yes 5-1
No 4-3
Indoor Indoor
Unit Unit
Indoor Indoor
Unit Unit