Toshiba MMY-MUP0721HT9P-UL Service Manual page 137

Miswiring example
Remote Header unit
Figure controller 7-segment
status display
Fig 1 No response E19, 02
Fig 2 E04 L08
Figure Status
The number of connected
outdoor units is few.
Fig 3
The number of connected
indoor units is few.
Fig 4
Header unit Header unit
Uv Uc Uv
U1 U2 U5 U6 U1 U2 U5 U6
U1 U2 U1 U2
Uv Uv
• Follower unit is incorrectly set to
header unit.
Header unit
Uh
U3 U4
U1 U2 A B
Uv
• Indoor/outdoor communication line is
miswired to Uh (U3/U4).
Header unit Follower unit
Uv Uc Uh
U1 U2 U5 U6 U3 U4
U1 U2 U1 U2
Uv Uv
• Outdoor communication line is miswired to Uh (U3/U4).
Header unit
Uv
U1 U2
U1 U2 A B
Uv
• Indoor/outdoor communication line is
miswired to remote controller terminal (A/B).
- 137 -
Miswiring example
Header unit
Line 1
Uc Uv
U1 U2
U1 U2
Uv
• Indoor/outdoor communication line is
miswired to header unit of other system.
Header unit
Uv
U1 U2
Wiring forgotten
U1 U2
Uv
• Indoor/outdoor communication line is
not connected.
Miswiring example
Header unit
Uv Uh
U1 U2 U3 U4
U1 U2
Uv
Header unit
Uv
U1 U2
U1 U2
Uv
• There is an indoor unit not connected to
the indoor/outdoor communication line.
Header unit
Line 2
Uv
U1 U2
U1 U2
Uv
U1 U2
Uv
Follower unit
Uc
U5 U6
U1 U2
Uv
Wiring forgotten
U1 U2
Uv