Megger (Programma) CSU 600A Current Supply Unit

Megger (Programma) CSU 600A Current Supply Unit

The Megger Programma CSU 600A is a high-current supply unit designed for primary current injection testing of protective relays, circuit breakers, and current devices. It is the test set utility commissioning teams, substation engineers, and electrical contractors in Ireland use when they need to inject high current through the primary circuit, not just through the relay terminals, and verify that the entire protection chain trips correctly under realistic fault conditions. Powerpoint Engineering supplies the CSU 600A as part of our authorised Megger distributorship, with calibration, accessory supply, and operator training to back it up.

The CSU 600A is the companion current source to the wider Megger Programma test family. Pair it with a Megger TM1700 / TM1800 circuit breaker analyser and a TM200 timer, and one substation outage covers timing, primary injection, and trip verification on a full protection scheme.

What primary injection testing actually proves

Secondary injection at the relay terminals proves the relay is wired and configured correctly, nothing more. It does not prove the CT ratio is right, the secondary wiring is intact, the trip coil is healthy, or that the breaker actually responds at the operating point in the relay setting. Primary current injection through the CSU 600A exercises the whole chain at the same operating point the protection will see during a fault, which is the only commissioning evidence that stands up against an asset owner's acceptance criteria.

That is the case for owning a CSU 600A, or for hiring one whenever a major commissioning or re-commissioning job lands on the schedule.

Key features

• Up to 600 A continuous primary current: sufficient for primary tests on protective relays, CTs, and circuit breakers across distribution-class switchgear.
• Variable current control: ramp from low current up to 600 A under operator control to capture pickup, dropout, and timing points cleanly.
• Stable, high-current output: repeatable injection for commissioning-grade test results that satisfy acceptance criteria.
• Integrates with Megger Programma timing kit: trigger interface for the TM200 digital timer and the TM1700 / TM1800 circuit breaker analysers.
• CSU 600A and CSU 600AT variants: the AT variant adds an integrated digital timer for self-contained primary injection plus timing in one unit.
• Site-ready build: portable enough for substation deployment, robust enough for the realities of the work.
• Quick-set rough current: rough current settings quickly and easily, then fine-trim for the test plan you are running.

Specifications: what to confirm before you order

Target users and applications

• Commissioning engineers verifying new protection schemes on substation switchgear
• Utility test teams running periodic primary current injection on the distribution network
• Industrial maintenance teams testing protection on plant transformers, motors, and incoming MV switchgear
• Renewable site test specialists commissioning protection on collector substations and generator transformers
• Electrical contractors providing protection commissioning and acceptance testing services to asset owners

Typical applications include CT ratio and polarity verification under primary current, overcurrent and earth-fault relay pickup testing, IDMT timing curves, trip-coil circuit verification under load, and acceptance testing of new protection schemes prior to energisation.

As authorised Megger distributor in Ireland, Powerpoint Engineering supplies the Megger Programma CSU 600A alongside the wider Programma timing and breaker-analyser range, and supports it with in-house calibration and repair.

FAQs

What is the difference between the CSU 600A and the CSU 600AT?

The CSU 600A is the standalone current supply unit, designed to be paired with an external timer such as the Megger TM200. The CSU 600AT integrates a digital timer in the same housing, removing the need for a separate timer instrument. For new test benches, the AT variant is usually the cleaner choice; for crews that already own a TM200, the standalone CSU 600A is often more cost-effective.

Can the CSU 600A test a relay without primary current?

The CSU 600A is a primary current source. For secondary injection at the relay terminals, the right tool is a dedicated relay test set. Many substation commissioning campaigns use both: secondary injection to commission the relay logic, and primary injection through the CSU 600A to commission the full protection chain.

Does the Megger Programma CSU 600A need calibration?

Yes. As a precision high-current source used for protection commissioning and acceptance testing, the CSU 600A should be recalibrated periodically. Powerpoint Engineering's calibration laboratory recalibrates Megger Programma current supply units in-house and supplies a traceable certificate.

To match the right Megger Programma CSU 600A configuration to your protection test bench, request a quote or speak to our team for compatibility advice.