IFB Board
The IFB board is used to translate between the MicroTech III
controller Modbus and the Daikin inverter compressor/outdoor
fan boards’ proprietary protocol.
There are three “ACS” communication current loop channels
available on the IFB board; ACS1, ACS2 and ACS3. ACS1 is
use for control of the inverter compressor (INV) and one or two
outdoor fans (OF1 and OF2). ACS3 is use for control of the
indoor expansion valve (EVI) and if the unit is a heat pump the
outdoor expansion valve (EVO). ACS2 is not currently used.
INV, OF1 and OF2 are controlled by a combination of
circuit boards designated A4P and A5P. These boards are
interconnected forming the ACS1 communication loop. On
208/230V units the A4P board controls both INV and OF1. On
460/575V units the A4P board controls only INV and there is
a separate A5P board that controls OF1. If a unit is equipped
with an OF2 it is controlled by a separate A5P control board.
Figure 3 shows the three possible board/loop arrangements
that make up the ACS1 loop.
Expansion valves EVI and if applicable EVO are controlled
by an expansion valve driver board EVB. The EVB board is
connected to the IFB board forming the ACS3 communication
loop. Figure 3 shows the ACS3 communication loop.
Figure 3: ACS Communication Current Loop Arrangements
For Troubleshooting Module-to-Module Communication, See page 70.
OM 1263 • MICROTECH UNIT CONTROLLER 6 www.DaikinApplied.com
To Next Page
Loading...
Need help?
General
