Wiring - Johnson Controls - 24-9890-1397 - T612DFH-4 - T612DFH-4+PIR - T612DFH-4 and T612DFH-4+PIR Thermostat Controllers with Fan Control and Occupancy Sensing Capability

T612DFH-4 and T612DFH-4+PIR Thermostat Controllers with Fan Control and Occupancy Sensing Capability Installation Guide

Johnson Controls
Product name
T612DFH-4 and T612DFH-4+PIR Thermostat Controllers with Fan Control and Occupancy Sensing Capability
Document type
Installation Guide
Document number
Document revision
Revision date
Product status

About this task

When an existing thermostat controller is replaced, remove and label the wires to identify the terminal functions. When a T612 Thermostat Controller is replaced, simply remove the old screw terminal blocks and reinsert them onto the PCB of the replacement thermostat controller.

  • Risk of Electric Shock.
  • Disconnect the power supply before making electrical connections to avoid electric shock.
  • Risque de décharge électrique.
  • Débrancher l'alimentation avant de réaliser tout raccordement électrique afin d'éviter tout risque de décharge électrique.
  • Risk of Property Damage.
  • Do not apply power to the system before checking all wiring connections. Short circuited or improperly connected wires may result in permanent damage to the equipment.
  • Risque de dégâts matériels.
  • Ne pas mettre le système sous tension avant d'avoir vérifié tous les raccords de câblage. Des fils formant un court-circuit ou connectés de façon incorrecte risquent d'endommager irrémédiablement l'équipement.
Important: Make all wiring connections in accordance with local, national, and regional regulations. Do not exceed the electrical ratings of the T612 Thermostat Controller.

To wire the thermostat controller:


  1. Strip the ends of each wire a 1/4 in. (6 mm) and connect them to the appropriate screw terminals as indicated in Table 1 and Figure 1 through Figure 3.
  2. Carefully push any excess wire back into the wall.
    Note: Seal the hole in the wall with fireproof material to prevent drafts from affecting the ambient temperature readings.
  3. Reinsert the screw terminal blocks onto the PCB.
    Note: If multiple wires are inserted into the terminals, be sure to properly twist the wires together prior to inserting them into the terminal connectors.
  4. For PIR models, carefully reattach the PIR connector to the PCB.
  5. Reattach the thermostat controller cover to the mounting base (top side first).
  6. Use a Phillips-head screwdriver to reinstall the security screw on the bottom of the thermostat controller cover, if desired. The security screw comes packaged separately in a plastic bag with the thermostat controller.
    Table 1. Terminal Identification (See Figure 1 )
    Terminal Number Terminal Label Function
    1 Fan-H Fan On – High
    2 Fan-M Fan On – Medium
    3 Fan-L Fan On – Low
    4 24 V~ Hot 24 VAC from Transformer
    5 24 V~ Com 24 VAC (Common) from Transformer
    6 BO5 Aux Aux BO (Auxiliary Output)
    7 BO5 Aux Aux BO (Auxiliary Output)
    8 BO3 Open Heat
    9 BO4 Close Heat
    10 BO1 Open Cool
    11 BO2 Close Cool
    12 BI1 Configurable Binary Input 1
    13 RS Remote Room Temperature Sensor
    14 Scom Sensor Common
    15 BI2 Configurable Binary Input 2
    16 UI3 Configurable Universal Input 3


Figure 1. Wiring the T612DFH-4 or T612DFH-4+PIR Thermostat Controller (See Table 1 )
Figure 2. Wiring the T612DFH-4 Thermostat Controller for On/Off Control
Figure 3. Wiring the T612DFH-4 Thermostat Controller for Floating Control