7
7-2. Connecting the Power Line and M-NET Transmission Line
CN16
V+/V-/FG
CN17
A/B/S
S
FG
M-NET
S / B /
A
(M1)
(M2)
U
U
R
Tightening torque for terminal screws: 1 N·m
Connect the device to a power supply unit (PAC-SC50KUA)
for the transmission line or an outdoor unit (either a centralized
control line or indoor control line can be connected).
* Only the M-NET circuitry of this device receives the power from the
M-NET transmission line. The power consumption factor is "1/4"
(equivalent to one ME Remote Controller).
Figure 7-1 Example of Connecting the Power Line and M-NET Transmission Line
PI controller
Circuit Onsite
(example)
Fuse
Varistor
Arrester
Noise
Filter
24 VDC
Power
source
AC Power Line
Uninterruptible
power supply
(UPS)
* Functional
ground
Varistor
Caution:
• Use a power line and M-NET transmission line that satisfy the specifications described in "6-1 Parts to Procured Locally".
• Attach a circuit comprising the following components to the supply primary side of the 24 VDC power supply.
(1) Varistor, (2) Arrester, (3) Noise filter, (4) Fuse
• It is important to pay attention to the polarity when connecting to the 24 VDC power supply terminal block.
Connecting the positive and negative in the reverse order will cause a failure.
• Fix the power line and M-NET transmission line in place on the outside to ensure that the terminal block is not affected by any
external force.
Not securely connecting and fixing the wires in place may cause heat generation and fire.
• Make sure that the copper wiring is not short-circuiting the plates (cover, lower case) or neighboring wires.
Cover the shielded line of the M-NET transmission line with materials such as vinyl tape and prevent short-circuiting with the
plates.
Note:
• Connecting an Uninterruptible power supply (UPS) is recommended in order to prevent the loss of pulse data in the event of a
power failure. If a UPS cannot be connected, try to make the AC power supply to the 24 VDC power supply as much same as
the power supply line to the meters.
• If this device is connected to an M-NET indoor control line and the outdoor unit is down because, for example, the power supply
is interrupted for servicing or there is a failure, the PI controller cannot be set and monitored from the system controller.