Watlow Series 146 Temperature Regulator

（5） Power and environmental specifications

Power parameters: Supports 24VAC (+10%/-15%), 120VAC (+10%/-15%), 230-240VAC (+10%/-15%), frequency 50/60Hz, maximum power consumption 10VA, power type needs to be specified by model (such as 1=120VAC, 2=230-240VAC, 3=24VAC).

Environmental conditions: working temperature 0-55 ° C (32-131 ° F), storage temperature -20-85 ° C (-4-185 ° F); Relative humidity 0-90% (non condensing), suitable for most industrial and commercial environments.

（6） Physical and installation specifications

Dimensions: Width 60mm (2.28 inches), height 115mm (4.45 inches), depth 100mm (3.89 inches), weight 0.3kg (0.7 pounds).

Terminal specifications: Captive screw cage clamping connection, supports maximum 4mm (0.155 inch) screwdriver head operation, compatible with 14-30 gauge wires.

Installation method: DIN rail installation (compatible with 35mm × 7.5mm rails) or embedded installation. Embedded installation requires drilling two 5mm (0.19 inch) holes on the panel and fixing them with # 8-32 screws.

Installation and Wiring Guide

（1） Installation process

1. Sub Panel Mounting

Attention: FM certification requires that limit switches be appropriately closed to reduce arbitrary adjustments to the set temperature.

Step 1: Use the controller as a template and mark two installation hole positions on the panel (refer to the hole size in Figure 2a of the document).

Step 2: Drill two 5mm (0.19 inch) diameter holes at the marked location.

Step 3: Use two # 8-32 screws to secure Series 146 to the panel.

2. DIN Rail Mounting

Step 1: Align the upper mounting clip of the controller with the upper edge of the DIN rail (refer to Figure 2b in the document).

Step 2: Press firmly on the upper edge of the front part of the controller, and the controller will be firmly fixed on the guide rail in a "snap" manner; If it cannot be fastened, check if the guide rail is bent. The clamping distance range of the guide rail is 34.8mm (1.37 inches) to 35.3mm (1.39 inches).

3. Disassemble from DIN rail

Step 1: Use your fingers to hold down the release lever at the bottom of the controller.

Step 2: Gently press the top of the controller (above terminals 1-9) and pull the release lever forward to remove the controller.

（2） Wiring specifications

1. General wiring rules

Use sensor types that match the device label model to ensure correct polarity of thermocouples or RTDs.

Thermocouples should be insulated from the installation surface during installation to avoid input errors caused by thermal conduction; Thermocouple leads should be made of twisted pair wires, wired separately, and kept away from other circuits.

In environments with severe electromagnetic interference (such as frequent switching of contactors, motors, and solenoid valves), shielded thermocouple leads should be used, and the shielding layer should only be grounded at the sensor end.

All wiring and fuse configurations must comply with the National Electrical Code (NEC NFPA70) and applicable local regulations; The independent load voltage needs to be fused on the L1 (live) side and connected to the common terminal (COM) of the relay.

It is recommended to install a power isolation switch near the controller to cut off the power supply in case of controller failure; The lead resistance of a 2-wire RTD can introduce errors (every 1 Ω lead resistance leads to additional errors). It is recommended to use a 3-wire RTD to compensate for lead resistance, and the three extension wires must have the same resistance (same wire gauge, copper stranded wire).

2. Power wiring

The power supply type is specified by the model: 120VAC corresponds to model 146_ -1_ -00000 230-240VAC corresponds to 146-2_ -0000, 24VAC corresponds to 146-3_ -0000.

Warning: To avoid the risk of electric shock, wiring must comply with national electrical safety standards. All wiring and fuses must comply with NEC and local regulations, otherwise it may cause equipment damage, property damage, or personal injury; The controller should be installed in an inconspicuous location to prevent unauthorized personnel from adjusting the set point. Only authorized personnel can operate the set point change, and unauthorized operation may cause safety risks; Applying incorrect voltage can cause irreversible damage to the controller.

3. Input wiring

Thermocouple wiring: Connect the positive and negative poles to the corresponding terminals as shown in Figure 3b of the document to ensure that the cold end compensation function is normal. Isolation and grounding thermocouples should be wired according to the model requirements.

RTD wiring: Refer to Figure 3c in the document for the wiring methods of 2-wire and 3-wire RTDs. The three leads of the 3-wire RTD need to have the same resistance. When wiring, pay attention to the correspondence between terminals S1 and S3 to ensure that the calibration curve matches (0.003850 Ω/Ω·° C).

4. Output wiring

The wiring of the electromagnetic relay (Form C type) should refer to Figure 3d in the document. The load should be connected in series between the normally open (NO) or normally closed (NC) terminal and the common terminal (COM). A fuse (recommended specification 1A) should be installed on the L1 side, and an RC suppressor should be connected in series for inductive loads.