Megger SPI500 Primary Injection Testing System
The Megger SPI500 is a high-current primary injection test system. It is specifically designed for substation testing, including applications for:
- Electronic reclosers
- Circuit breakers
- High-speed fuses
- Ground fault relays
The SPI500 can control up to two SPI500B boosters:
This expands its capability to three times its original output.
One of the standout features of the SPI500 is its unique control system. This system dynamically adjusts the output to maintain a constant current, even if the load impedance changes during tests.

For ease of use, the SPI500 can be controlled in different ways:
- Manually
- STVI allows manual testing without the need for a laptop
- Automatically using the Smart Touch View Interface (STVI)
- Simplifies input and control through a user-friendly touch screen, removing the complex menu systems of traditional primary injection test systems.
- Through a PC for fully automated testing and report generation
- Automatically regulates output, compensating for test sample heating or changing load impedance. It delivers the desired current without further user intervention.
Megger SPI500 Applications:
The Megger SPI500 is versatile, suitable for high-current commissioning tests and low-voltage molded-case circuit breaker testing. It provides up to 2500 A output with the main unit, 5000 A with one booster, and up to 6500 A with two boosters. The SPI500 adapts output levels sub-cycle, accommodating devices with fluctuating impedance, such as self-powered reclosers, which change impedance during charging or power draw.
Megger SPI500 Key Features:
- 2500 A output with the main unit
- Up to 6500 A output with two boosters
- Auto-detects 120 or 240 V input voltage
- Designed for testing self-powered reclosers, high-speed fuses, circuit breakers, and ground fault relays
- Includes software with hundreds of circuit breaker TCC curves
- Enhanced Testing: Unlike traditional systems that require manual adjustments for test current and maintaining output, the SPI500 ensures stable, continuous output throughout the test.
- Manual Control: The STVI allows manual testing without the need for a laptop.
- DC Offset Elimination: The Megger SPI500 prevents DC offset during tests, adhering to ANSI/NEMA AB 4-2023 standards, ensuring accurate results when testing low-voltage circuit breakers.

- Current Decay Prevention: The SPI500 eliminates current decay, maintaining a steady current throughout the test, which prevents inconsistent results. Current decay ⇨ Current decay eliminated:

- Construction and Protection: Built for reliability, the SPI500 is designed to withstand frequent transportation, featuring rugged instrumentation and built-in protective devices such as fuses, circuit breakers, and temperature sensors to prevent overheating.
The Megger SPI500 system is the ideal solution for high-current primary injection testing, providing consistent, accurate, and automated results while reducing the need for manual intervention.
What comes with the Megger SPI500?
- Megger SPI500 Primary Injection Testing System
- (2001-487) Accessory carry case
- (684006) Alligator clip (red 4.1 mm)
- (684007) Alligator clip (black 4.1 mm)
- (2008-539-2) Sleeved test leads (1 x red, 1 x black, 200 cm, 600 V, 32 A CAT II)
- (1004-728) Current lead for 125A Tap: AWG#6 61 cm long (2 ft)
- (1008-280) Current lead: AWG 4/0 61 cm long (red 2 ft)
- Power cord
- (1003-863) High current alligator clamp: assembly (100 A)
- (1003-864) High current alligator clamp: assembly (75 A)
- (2003-732) High current probe: 7.6 mm diameter (0.3 in)
- (2003-733) High current probe: 5.1 mm diameter (0.2 in)
- (2003-734) High current probe: 3.2 mm diameter (0.125 in)
- (90003-684) Ethernet cable: for interconnection to PC 210 cm long (7 ft)
- (891040) SPI500 manual and software accessory kit