Megger MS-2A Circuit Breaker & Overcurrent Relay Test Set
- Megger MS-2A circuit breaker and relay test set delivers portable primary-injection testing for breakers, overload relays, overcurrent relays, and ground-fault trip devices with adjustable high-current output up to 750 A and integrated timing.
Detailed Overview
Circuit Breaker and Overcurrent Relay Testing with Megger MS-2A
The Megger MS-2A circuit breaker and overcurrent relay test set solves the field challenge of applying controlled high current while measuring protective-device trip behavior. Its integrated configuration combines variable AC output, ammeter measurement, timer control, and a portable enclosure for breaker, relay, overload, ground-fault, CT ratio, and panelboard meter test workflows.
High-Current Primary Injection for Protective Device Testing
The MS-2A supports primary-injection testing by delivering adjustable AC current through selectable output ranges. Momentary and maintained output modes help match the test method to instantaneous trip checks, time-delay verification, and device operation timing.
- Adjustable AC output ranges from 0 to 5 A, 0 to 25 A, 0 to 120 A, and 0 to 240 A
- Short-duration output up to 750 A through a typical 125 A molded-case circuit breaker
- Momentary and maintained output modes for trip-current and time-delay testing
Integrated Current Measurement and Trip Timing
The Megger MS-2A combines current readout and timing functions to reduce the need for separate measurement setup during protection testing. Ammeter memory mode, multiple current ranges, and timer control conditions support repeatable capture of trip current and operating time across common protective-device configurations.
- Ammeter ranges of 0 to 1.999 A, 19.99 A, 199.9 A, and 750 A
- Timer ranges of 0 to 99.999 seconds, 0 to 999.99 seconds, and 0 to 99999 cycles
- Timer control for current-actuated, normally closed, and normally open test circuits
Protection Testing Use Across Breakers, Relays, and Metering Workflows
The Megger MS-2A supports electrical protection maintenance where technicians need to confirm that protective devices operate at the intended current and within the expected trip time. Its test scope extends from molded-case circuit breakers and overcurrent relays to motor overload relays, ground-fault trip devices using window CTs, current transformer ratio checks, and panelboard ammeter or voltmeter testing.
- Molded-case circuit breaker testing for time-delay and instantaneous trip operation
- Overcurrent relay and motor overload relay testing for protective-device response checks
- Ground-fault trip device, CT ratio, panelboard ammeter, and panelboard voltmeter testing
Key Benefits
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✓Fully Tested & Certified
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✓30-Day Risk-Free Returns
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✓1-Year Full Warranty
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✓Professional Calibration Services
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✓Trade-In Program Available
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✓Fast & Reliable Delivery
What's in the Box
- 1 x Megger MS-2A-230 Circuit Breaker & Overcurrent Relay Test Set
- 2 x Red test leads, 200 cm, Cat. No. 620143
- 2 x Black test leads, 200 cm, Cat. No. 620144
- 2 x Red alligator clips, Cat. No. 684006
- 2 x Black alligator clips, Cat. No. 684007
- 2 x No. 2 high-current leads, 2 ft, Cat. No. 620155
- 5 x 0.125 A, 250 V MDL fuses, Cat. No. 981
- 1 x Instruction manual, Cat. No. 750026
- 50 x Green test/maintenance record cards, Cat. No. 2239
- 50 x Buff test/maintenance record cards, Cat. No. 2238
- 1 x Universal travel power adapter
Technical Specifications
| Input | |
|---|---|
| Input Voltage | 230 V input version |
| Frequency | 50/60 Hz |
| Phase | 1φ |
| Output | |
| Output Ranges | Continuously adjustable in four ranges: 0 to 5 A at 120 V max; 0 to 25 A at 24 V max; 0 to 120 A at 6 V max; 0 to 240 A at 3 V max |
| Output Capacity | Designed to permit short-duration overloads; output ranges provide several times their current rating when output voltage is sufficient for the test-circuit impedance |
| Time-Delay Test Capability | Devices rated up to 125 A using a test current of three times rating, 375 A |
| Instantaneous Trip Test Capability | 750 A through a typical 125 A molded-case circuit breaker connected with the supplied test leads |
| Overload Capability | 100% rated current: 30 min on / 30 min off; 200% rated current: 3 min on / 8 min off; 300% rated current: 30 s on / 4 min off |
| Output Initiate Circuit | Solid-state output initiating circuit using a triac instead of a contactor |
| Output Duration Modes | Momentary and maintained |
| Instrumentation — Ammeter | |
| Operating Modes | Memory; Normal |
| Display | 3-1/2 digit, extra-bright LED display with 0.3 in. numerals |
| Ranges | 0 to 1.999 A; 19.99 A; 199.9 A; 750 A |
| Continuous Accuracy | ±1% of reading, ±1 digit on three high ranges; ±1% of range, ±1 digit on low range |
| Instrumentation — Timer | |
| Display | 5-digit, extra-bright LED display with 0.3 in. numerals |
| Ranges | 0 to 99.999 s; 0 to 999.99 s; 0 to 99999 cycles |
| Accuracy | ±0.005% of reading, ±1 digit |
| Timer Control Circuit | |
| Timer Start / Stop | Automatically starts when output is energized; automatically stops timer and de-energizes output when the device under test operates |
| Current Actuated Mode | For devices with no auxiliary contacts to monitor; timer stops when output current is interrupted |
| Normally Closed Mode | For devices with normally closed contacts; timer stops and output is de-energized when contacts open |
| Normally Open Mode | For devices with normally open contacts; timer stops and output is de-energized when contacts close |
| Physical | |
| Enclosure | High-strength molded suitcase-type enclosure with carrying handle, removable cover, and storage space for test leads |
| Standards | CE; EN 61326-2-1; EN 61010-1; EN 61010-031 |
| Dimensions | 18 W × 9.5 H × 13.5 D in. |
| Weight | 33 lb |
| Ordering Information | |
| Model | MS-2A |
| Catalog Number | MS-2A-230 |
(Including Calibration Support & Trade-In Options)