82
Electrical Wiring
Electric circuit example – PACi systems
Single-connection system
10P Connector
Blower signal
output
X1
4
5
6
7
AHU Kit
X1
Blower
signal
Field-supplied
X2
Method B: For multi-step or inverter mode fan control by external BMS
When the AHU fan is controlled by an external building management system in a multi-step or
inverter mode (e.g. based on a room CO
2
sensor or a room supply pressure control or similar),
the simple on/off contact method (as in Method A) may not be satisfactory. In such cases, it
is strongly recommended to install a fi eld-supplied diff erential pressure switch and/or air fl ow
switch in the AHU duct(s), in order to enable outdoor unit operation only when suffi cient air vol-
ume fl ow is present.
The following diagram shows just one wiring example of several possibilities.
For the PAW-T10 contacts used in this wiring system to work properly, the following require-
ments must be observed:
● On the AHU Kits’s integrated remote controller, invoke the “Detailed Settings” mode
and set parameter “2E” to “0001”. (For details on the “Detailed Settings” mode,
see the operating instructions of the relevant remote controller model or the ECOi/
ECO G or PACi service manuals.)
● Make sure that jumper JP1 on the indoor unit PCB remains closed/intact.
As an alternative to using PAW-T10 terminals 1 and 2, it is also possible to use for example con-
tacts 1 to 4 in Section C of the main control board (“COM” and “DI1” to “DI3”). For correct use of
these contacts see “5.4 Terminal board layout” in this manual.
The wiring system shown in the diagram provides the following control functions:
● During the fi rst 3 minutes after unit has been switched to “ON” (either by BMS or
by local remote controller), the delay timer relay will keep the PAW-T10 contacts
closed and operation is permitted.
● After the AHU fan has been started and while the air volume fl ow is suffi cient, the
air fl ow switch will keep the PAW-T10 contacts closed so that operation continues.
● Once the set delay time has elapsed, the timer contact will be opened, but the
PAW-T10 contacts will stay closed due to the air fl ow switch relay.
● When the air volume fl ow drops below the lower limit, the air fl ow switch will
open the PAW-T10 contacts and the outdoor unit will stop operation. At the same
time the remote controller in the AHU unit will be locked to prevent unintentional
operation.
● The minimum air volume fl ow should be set on the air fl ow switch according to the
required minimum air volume fl ow of each AHU Kit model.
Summary of Contents for PAW-160MAH2
Page 3: ...Air Handling Unit Kit Installation Instructions SET AL1 OUT ATU PV SV ºC ºC ...
Page 4: ......
Page 99: ...97 ...
Page 100: ...Notes ...
Page 101: ...Notes ...