TM_s-MEXT_ME28relC_00_12_19_EN
Technical manual
TRANSLATION OF THE ORIGINAL INSTRUCTIONS
122
20.10.3
Remote keyboard up to 200 metres
To connect a
remote keyboard two “T” shunt boards must be used, one near the controller and one near the remote keyboard.
In case of a remote keyboard monitoring a single unit for a distance of less than 200 metres, the correct configuration is as follows.
Figure 20-11:
Electric diagram for connecting a remote keyboard at a distance of up to 200 m
20.10.4
Remote keyboard from 200 metres up to 500 metres
If the remote keyboard must be installed over 200m away from the local network (LAN), a power unit must be installed near the remote keyboard.
The remote keyboard cannot be installed more than 500 m away.
The only difference between this and a remote keyboard up to 200 metres is that the power unit must be to terminals 1 and 2 of the T shunt (the one near the remote
keyboard). In this case a 3-wire cable connecting the two T-shunts is sufficient.
If just one chiller is connected, the connection diagram is:
Figure 20-12:
Electric diagram for connecting a remote keyboard at a distance between 200 m and 500 m
20.10.5
Remote keyboard for more than one unit
To connect more than one chiller to the same remote keyboard, connect the two boards together by jumpering connectors J11.
A configuration similar to the two shown above should only be used on the first board in the network (the one nearest the remote keyboard).
Figure 20-13:
Basic scheme to connect a remote keyboard to more units
6x1 mm
2
shielded and
twisted
Unit
Unit
3x1 mm
2
shielded
and twisted
or
3x1 mm
2
The highlighted part must be included for distances
between 200 and 500m
Unit 1
Unit X
Last unit
3x1 cable on connector J11
to other units
