Electrical testing services
Switchgear Testing
Acceptance and maintenance testing for low- and medium-voltage switchgear assemblies — verifying insulation integrity, connection quality, and protective device operation to NETA standards.
Switchgear Is Only as Reliable as Its Last Test
Switchgear is the control and protection hub of any power distribution system. It houses the circuit breakers, bus, and protective devices that route power, isolate faults, and protect downstream equipment. When switchgear fails — whether from insulation breakdown, connection degradation, or a protective device that fails to operate — the consequences range from extended outages to arc flash events that endanger personnel.
J. Wesley Services Group performs switchgear testing in accordance with NETA ATS and MTS standards on new installations and in-service equipment. We test the full assembly — bus, connections, insulation, and protective devices — and deliver complete test reports that document the condition of every component.
Tests We Perform
Insulation Resistance Testing
Megger testing of bus insulation, phase-to-phase and phase-to-ground, to verify insulation integrity. Identifies moisture, contamination, and insulation degradation that could lead to tracking or flashover under operating voltage.
Contact and Bus Resistance Testing
Micro-ohmmeter testing of bus joints, cable terminations, and circuit breaker contacts to verify low-resistance connections throughout the assembly. Elevated resistance at any connection point generates heat that accelerates degradation.
Circuit Breaker Testing
Complete testing of all circuit breakers within the switchgear assembly including contact resistance, insulation resistance, primary injection, trip timing, and protective relay verification. See our Circuit Breaker Testing page for full details.
Protective Relay Testing
Functional testing and calibration of all protective relay elements associated with the switchgear, including overcurrent, ground fault, and differential protection. Verifies that protection will operate correctly at specified settings.
Control Wiring Verification
Verification of control wiring continuity, correct termination, and proper operation of all control circuits including trip, close, alarm, and indication functions. Identifies wiring errors and connection problems before energization.
Infrared Thermography
Thermal imaging of energized switchgear to identify hot spots in bus connections, breaker contacts, and cable terminations. Performed as part of maintenance testing with equipment energized and under load.
Switchgear Types We Test
- Metal-clad medium-voltage switchgear (5 kV – 38 kV)
- Metal-enclosed medium-voltage switchgear
- Low-voltage switchgear and switchboards
- Motor control centers (MCC)
- Padmounted and submersible switchgear
- Automatic transfer switches (ATS)