Osna Electronics · Protection Relays
Osna Electronics WE-77-EX-ERU repair
Component-level repair for the Osna Electronics WE-77-EX-ERU (earthing relay unit), onsite or sent in from anywhere in India. The diagnosis and repair cost are confirmed before any work starts.
Cost confirmed before any work starts · Warranty of 30 days to 6 months
At a glance
The Osna Electronics WE-77-EX-ERU
- Manufacturer
- Osna Electronics
- Model / part number
- WE-77-EX-ERU
- Also searched as
- WE77EXERU · WE 77 EX ERU
- Description
- Earthing relay unit
- Category
- Protection Relays
- Service
- Diagnosis and component-level repair, onsite or ship-in
- Warranty
- 30 days to 6 months, confirmed before work starts
Osna Electronics equipment in this catalog is listed by model or part number. Send the model from the nameplate and the fault, and it will be matched to an engineer who works on that kind of unit.
Common faults
What usually fails on a unit like the WE-77-EX-ERU
Protection relays have to trip when needed and stay quiet otherwise, so a repaired relay must be tested against its settings, not just powered up. Power supplies, input boards, displays and output contacts are the usual failure points.
Relay dead or rebooting
Failed internal power supply, often from age or a surge on the auxiliary supply.
Self-supervision or internal fault alarms
Faults in the processor board, memory or analog input stages.
Wrong measurement
Current or voltage inputs reading wrongly because of damaged input transformers or analog circuits.
Output contacts not operating
Burnt or welded output relay contacts, or failed driver circuits.
Display and keypad faults
Unreadable displays and dead keys, which make settings hard to check.
Relays and contacts
Relay outputs are checked for contact resistance and correct operation, since worn contacts give intermittent faults.
First checks
What to check before calling an engineer
Isolate and lock out the supply, and wait for stored energy to discharge, before opening anything.
Safe for plant staff
- Record any self-supervision alarm and the event log.
- Check the auxiliary supply voltage.
- Keep a copy of the settings file.
Leave to a specialist
- Secondary injection testing after repair.
- Changing or uploading relay settings.
- Any work on CT and VT circuits: open CT secondaries are dangerous.
Getting it fixed
How to get the WE-77-EX-ERU repaired
What to send with it
- The relay, with its settings file if possible.
- The alarm or event log.
- The CT and VT ratings it is set for.
Onsite or ship-in
Technicians work onsite from our Hyderabad base and travel to plants across India; anything that can be removed can also be sent to MachineryFix from anywhere in the country.
Warranty. Repairs carry a warranty of 30 days to 6 months, depending on the item and the repair; the exact term is confirmed before work starts.
FAQ
WE-77-EX-ERU repair questions
How is the Osna Electronics WE-77-EX-ERU tested after repair?+
Beyond powering up, the relay is checked with secondary injection so its measuring inputs, protection functions and output contacts are confirmed to work.
Does the Osna Electronics WE-77-EX-ERU have to be sent in, or can an engineer come to the plant?+
Either. An engineer can diagnose it in place and repair it there or take it away, or the unit can be sent to MachineryFix from anywhere in India. The diagnosis and repair cost are confirmed before any work starts.
Is MachineryFix connected to Osna Electronics?+
No. Osna Electronics and the model name are used only to identify the equipment. MachineryFix is an independent repair service and is not affiliated with or endorsed by Osna Electronics.
Other manufacturers
Protection Relays from other makers
Osna Electronics and WE-77-EX-ERU are named only to identify the equipment. MachineryFix is not affiliated with or endorsed by Osna Electronics.
WE-77-EX-ERU down?
Send the fault and what the machine was doing. We'll match an engineer who works on it.