ELECTRICAL HOOK-UP – TORQUE OVERLOAD BOX (7-1)
This procedure is used to wire, verify, and function-test the torque overload box, confirming that the limit switches and overload trip respond correctly before the equipment is returned to service.
City of Savannah - Reclamation
03/02/2026
ELECTRICAL HOOK-UP – TORQUE OVERLOAD BOX (7-1)
This procedure outlines the steps for wiring and testing a torque overload box (7-1) so that it is connected safely and operates correctly. It guides the technician through terminal identification, ground, 120 VAC and limit switch connections, continuity checks, and an energized function test, followed by a review of common wiring errors.
Locate terminal strip. Identify: 1. 120 VAC HOT terminal 2. Limit Switch #1 return 3. Limit Switch #2 return 4. Ground terminal ⚠ Confirm terminal numbers from wiring diagram before landing wires.
1. Land equipment ground conductor. 2. Torque terminal securely. 3. Verify bonding to enclosure. ✔ Ground must be connected before control wiring.
1. Verify conductor insulation intact. 2. Strip properly (no nicked strands) 3. Land HOT wire on designated terminal. 4. Torque to manufacturer spec. ⚠ Confirm correct voltage (120 VAC).
You should have two return conductors going back to PLC or control panel. 1. Identify Limit Switch #1 terminal. 2. Land return wire. 3. Identify Limit Switch #2 terminal. 4. Land return wire. 5. Verify tightness. ✔ No loose strands ✔ No exposed copper
Before energizing: 1. Check continuity through switch. 2. Manually actuate torque linkage. 3. Verify switch changes state. 4. Confirm proper PLC input response (if possible).
Remove LOTO. (CALL OPERATIONS) 1. Apply control power only. Verify: 2. No immediate trip. 3. Torque switch changes state when manually actuated. 4. Jog motor briefly. 5. Confirm overload trip stops motor. ✔ Confirm correct rotation. ✔ Confirm trip resets properly.
1. HOT and return reversed 2. Missing ground 3. Loose terminal screws 4. Wrong contact (NO vs NC) used 5. Control voltage mismatch
Source: City of Savannah - Reclamation (Community Member)