Ifb Board - Daikin MicroTech III DPS Installation And Maintenance Manual

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
Figure 3: ACS Communication Current Loop Arrangements
For Troubleshooting Module-to-Module Communication,
OM 1263 • MICROTECH UNIT CONTROLLER
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 .
See page 70 .
6
Introduction
www .DaikinApplied .com