Megger VIDAR Vacuum Interrupter Tester

Megger VIDAR Overview

The Megger VIDAR is a portable tester used to verify the vacuum integrity of vacuum interrupters in medium-voltage switchgear. A vacuum circuit breaker can only interrupt a fault current if the vacuum inside its interrupter is intact; over time that vacuum can degrade, leaving the breaker unable to do its job safely. The VIDAR confirms the condition of the vacuum quickly, in the field or on the shop floor, without having to dismantle the interrupter.

The VIDAR applies a DC high voltage across the open contacts and uses the established relationship between flashover voltage and vacuum integrity to assess the chamber. The test voltage is switchable in standard steps from 10 to 60 kV DC, plus one customised value set per order, and the result is shown simply as a green light for a good interrupter or a red light for a defective one; a pass corresponds to a measured leakage current below 0.3 mA. For safety it requires two-handed operation and warns the operator whenever high voltage is present. Weighing about 7 kg and supplied in a transport case, it follows ANSI/IEEE DC test practice.

The Megger VIDAR (part no. BR-29090) is for switchgear technicians, substation maintenance teams and breaker service shops who need a quick pass or fail on whether a vacuum bottle still holds its vacuum before the breaker goes back into service. Megger notes that vacuum chambers do not last forever: leakage can start after years or decades and is usually rapid once it begins, and dirt on the poles or the bottle surface can also make a breaker unsafe. The VIDAR applies DC across the open contacts and checks that the gap withstands the test voltage, so the bottle does not have to be removed.

From Megger’s VIDAR datasheet: five switchable standard voltages of 10, 14, 25, 40 and 60 kV DC, plus one customised voltage between 10 and 60 kV set at the factory (50 kV by default). Accuracy is 0 to −15% and ripple is 3% at most. The red lamp lights if the current exceeds 0.3 mA, green means the chamber passed, and yellow means the test was interrupted, for example when a one-minute test is repeated less than two minutes after the last one. Both TEST knobs must be turned at the same time to apply high voltage, and the internal high-voltage circuit discharges in 0.3 s at most. It runs on 115/230 V AC, 50/60 Hz (69 VA max), works from −10 to +50 °C, measures 250 × 210 × 125 mm and weighs 6.9 kg, or 8.4 kg with accessories and case.

Choosing the test voltage, per Megger: use the DC voltage the breaker manufacturer recommends. Otherwise multiply the manufacturer’s AC test voltage by √2, and with no data at all use 2.5 × the breaker’s nominal voltage. The DC method is described in IEEE C37.20.3, and IEC 62271-1 and IEEE C37.06 give guidance on test levels. Clean and dry the bottle first: Megger says a polluted surface is the most common reason a good bottle fails the test.

MME is an authorized Megger representative in the UAE. See the Megger range and our circuit breaker testers. For timing and coil current on the same breakers, see the Megger EGIL circuit breaker analyzer, the Megger EGIL200 or the Megger TM1700; for contact resistance, the Megger MOM200A micro-ohmmeter.

Megger VIDAR Key Features

What the VIDAR gives a switchgear team:

• Tests vacuum integrity of vacuum interrupters in MV switchgear.
• DC high-voltage test method based on flashover-voltage / vacuum relationship.
• Switchable test voltages of 10, 14, 25, 40 and 60 kV DC, plus one customised voltage set per order.
• Simple green (pass) / red (fail) verdict; pass current below 0.3 mA.
• No need to dismantle the interrupter — test in place.
• Two-handed control and high-voltage warning for operator safety.
• Portable (~7 kg) in a transport case for field and workshop use.

Megger VIDAR Applications

Where the VIDAR is used:

• Verifying vacuum integrity of vacuum circuit breakers in MV switchgear.
• Field and shop-floor testing without disassembly.
• Commissioning and periodic maintenance of vacuum interrupters.
• Condition assessment following ANSI/IEEE DC test standards.

What’s in the Megger VIDAR Box

What comes with the VIDAR (BR-29090):

• VIDAR vacuum interrupter tester.
• Permanently mounted 5 m (16 ft) cable set and ground cable.
• Mains lead, transport case (GD-00030) and user documentation.

The customised test voltage is configured per order (default 50 kV); contact MME to confirm your configuration.

Megger VIDAR questions

What switchgear teams ask before ordering:

• Can I choose my own test voltage? Yes, one. Besides the five standard steps, one voltage between 10 and 60 kV DC is set at the factory to your order; the default is 50 kV.
• Why DC rather than AC? With AC, the capacitive current is 100 to 1000 times larger than the resistive current that shows the vacuum condition, so it is hard to read and needs much heavier equipment than the 7 kg VIDAR.
• Is there a version for railway vacuum breakers? Megger lists a Sécheron model, part no. BR-29092, for vacuum train circuit breakers.

Why Buy the Megger VIDAR from MME in UAE

MOHAMMAD MAHDI Electronics Trading LLC (MME) is a trusted supplier of Megger test and measurement equipment across the UAE and the wider Gulf region. We offer genuine Megger products, competitive pricing, expert application support and reliable after-sales service to keep your switchgear testing programme running smoothly.

Download the Megger VIDAR datasheetPDF