No-volt, phase-failure and reverse-power protection at the grid interface
An NVR (no-volt relay) panel disconnects the solar plant or consumer installation from the grid when the DISCOM supply fails, drops a phase, or when power flows in the wrong direction — protecting utility linemen from back-fed solar generation and meeting the DISCOM’s net-metering connection conditions. Accu-Panels Energy manufactures NVR panels from 32 A to 800 A with under/over-voltage, phase-sequence and reverse-power relays, contactor or MCCB tripping and auto-reclose logic, at its Ahmedabad works.
Its particular special feature is it automatically trips incoming power whenever one of three phases fails with a special kind of relay in conjunction used with a contactor, spd, mcb, A/M selector switch. After the operation of the relay, the relay doesn’t reset to its original position until all the phases become healthy.
Protection Level
Firstly, all indoor panels have protected with IP54 or better even more all outdoor panels have protected with IP65 or better. Secondly, all PCC Panels made by laser cutting CRCA sheet and powder coating with the 7-Tank process. In addition, Accu-panels have provided IP65 certificates for solar acdb dcdb.
Features
- Firstly Safe
- Secondly Durable
- Thirdly High performance
- Also Sturdy construction and
- Finally Corrosion resistance
- Customized 3phase configuration as per SPV Plant capacity for different Kwp capacity & Ampere range up to 800Amp
- With Branded Switch gears for more reliability & safety
- Combined with the control circuit for disconnection while needed; Digital Voltmeter on request
- Precision Sheet Metal Enclosure with practical design for cable entry
- Supplied with unique Wall Mounting clamp & Letter/wiring plan pocket
- 45-degree flange profile along with Joint less Gasket for superior protection from moisture, dust & insects
- Customized Powder coating shade available
- 415 V AC, 3-phase 4-wire, 50 Hz; 32 A to 800 A
- Protection: under-voltage (typically 80 %) and over-voltage (110 %), under/over-frequency (47.5–51.5 Hz settable), phase failure and phase sequence, reverse power (directional relay with CTs) per DISCOM net-metering conditions
- Tripping device: contactor up to 400 A, motorised MCCB above; auto-reclose after a settable healthy-supply delay (e.g. 60–300 s)
- Indications: mains healthy, trip cause lamps, hooter; optional Modbus alarm output
- Assembly per IEC 61439-1; relays per IEC 60255; IP54 indoor / IP65 outdoor (IEC 60529)
- 1.6 mm CRCA enclosure, 7-tank pre-treatment, powder coated; wall-mounted
Using in Solar Power Plant, Rooftop power plant, Solar plant, Renewable energy Source, and any type of solar power plants. Also using for LT power distribution in electricity. Using in Solar Power Plant, Rooftop power plant, Solar plant, Renewable energy Source, and any type of solar power plants. Also using for LT power distribution in electricity.
Where the NVR panel sits
Between the solar ACDB and the consumer’s main LT panel or the DISCOM meter, so that the inverters are isolated from the grid whenever the grid is abnormal. On plants above 1 MW it is combined with the TVM / ABT metering panel and, for hybrid sites, with the DG–solar synchronising logic that blocks reverse power into the DG.
Frequently asked questions
Why does the DISCOM insist on an NVR panel?
To guarantee that a solar plant cannot energise a dead grid (anti-islanding at the installation level) and that export is limited or blocked where the connection agreement requires it.
Don’t inverters already have anti-islanding?
Yes, but the utility requires an independent, visible isolation device with adjustable settings and a lockable position; the NVR panel provides it.
Can the NVR panel prevent export?
Yes. A reverse-power relay trips the incomer or signals the inverters to curtail when power flows towards the grid beyond the set limit.
Does it reclose automatically?
Yes, after the supply has been healthy for the set delay, so the plant restarts without an operator.
Send your DISCOM connection conditions and plant kW to our team for an NVR panel offer.
