The Enphase Q Relay (Q-RELAY-1P-INT) is the single-phase grid disconnection device at the heart of every UK Enphase IQ7 IQ8 and IQ9 Series microinverter system. Mounted directly in the consumer unit or a dedicated enclosure, it continuously monitors grid voltage and frequency and physically isolates the array the instant conditions fall outside safe limits — then automatically reconnects once the grid is stable again, without a callout or manual reset.
230 V
Nominal Grid Voltage
15
Max IQ7 Microinverters
Installer Requirement: The Q Relay must be installed and wired by a qualified electrician in accordance with BS 7671 and the Enphase installation manual. Isolate the mains supply before connecting any wiring to avoid the risk of electric shock.
Microinverter Compatibility Note: The maximum number of microinverters per Q Relay varies by model — from 15 × IQ7 down to 7 × IQ8P — because higher-output IQ8 units draw more current per circuit. Confirm the exact array size against your chosen microinverter model before ordering, and note that a maximum of 4 active Q Relays is permitted per system.
Smart Grid Communication: The Q Relay communicates over power line communication (PLC) with the Enphase Envoy, allowing remote firmware upgrades and system-wide coordination without any additional control wiring between devices.
Automatic Grid-Fault Disconnection
The relay's dual monitoring circuit tracks both voltage and frequency independently, so it can isolate the array from a wide range of grid anomalies — not just simple over/under-voltage events — keeping the installation compliant with anti-islanding requirements.
Integrated DC Injection Sensing
Because microinverters convert DC to AC at the panel, a fault could in theory push DC current onto the AC grid. The Q Relay senses this condition directly and trips the circuit, removing the need for a separate DC injection monitor in the installation.
Self-Resetting Operation
Rather than requiring a site visit after every grid disturbance, the relay automatically reconnects once voltage and frequency return to within spec for the required settling period, minimising downtime and callouts for the installer.
Compact 3TE DIN-Rail Footprint
At just 53 mm wide, the relay occupies only three standard DIN-rail module widths, making it easy to fit inside an existing consumer unit or a small dedicated enclosure alongside other protective devices.
Dual-LED Diagnostics
Two independent red/green LEDs separate voltage status from frequency and DC injection status, letting an installer diagnose the specific cause of a trip at a glance without test equipment.
Remote Firmware Upgradable
Firmware can be updated over the same PLC link used for monitoring, so the relay's protection algorithms can be kept current with evolving grid codes without physically revisiting the unit.
| Electrical & Mechanical Specification |
Details |
| Model Number |
Q-RELAY-1P-INT |
| Configuration |
Single-phase grid disconnection relay (50 Hz) |
| Nominal Grid Voltage |
230 V |
| Minimum / Maximum Grid Voltage |
85–265 V |
| Rated Current |
20 A |
| Nominal Frequency |
50 Hz |
| Minimum / Maximum Frequency |
45 / 55 Hz |
| Trip Time |
100 ms |
| Output |
2-pole, normally open (L1 and N) |
| Maximum Microinverters per Relay |
15 × IQ7 · 12 × IQ7+ · 11 × IQ7X · 10 × IQ7A · 11 × IQ8MC · 10 × IQ8AC · 9 × IQ8HC · 9 × IQ8X · 7 × IQ8P |
| Maximum Relays per System |
4 active Q Relays |
| Overvoltage Category (IEC 61010-1) |
III |
| Pollution Degree (IEC 61010-1) |
2 |
| Power Consumption |
10 VA |
| Surge Protection (L1, N, Output) |
2 kV (L-N) |
| Communication |
Power line communication (PLC), 110–120 kHz (Class B), narrowband 200 Hz |
| LED Indicators |
Two red/green LEDs — one for under/over-voltage trip, one for under/over-frequency and DC injection |
| Mounting |
35 mm DIN rail (standard) |
| Conductor Size |
2.5–6 mm² |
| Dimensions (W × H × D) |
53 × 90 × 58 mm |
| Width |
53 mm / 3 TE |
| Weight |
160 g |
| Operating Temperature Range |
-40°C to 50°C |
| Storage & Transport Temperature Range |
-40°C to 50°C |
| Relative Humidity |
0–85% (non-condensing) |
| Maximum Altitude |
<2,600 m |
| IP Rating |
IP20 (must be installed in a protected environment) |
| Grid Connection Standards |
EN 50549-1, VDE-AR-N 4105:2018, NA/EEA-NE7-CH 2020, TOR Erzeuger Typ A, UNE 217002:2020, EN 50438:2013, DANSK 2019, EIFS 2018, VJV 2018, C10/C11 |
| Safety Standards |
BS EN 61010-1 (2012 ed. 3), BS EN 61010-2-030:2017 |
| EMC / EMI Standards |
IEC 61326-1, BS EN 61000-3-11, BS EN 61000-3-12, BS EN 50065-1, EN 50065-2-2 |
| Product Labelling |
CE, RCM |
What does the Enphase Q Relay do?
It acts as a physical grid disconnection device for Enphase IQ7 and IQ8 Series microinverter systems, continuously monitoring grid voltage and frequency and isolating the array within 100 ms of an out-of-spec condition, then reconnecting automatically once the grid stabilises.
How many microinverters can a single Q Relay support?
This depends on the microinverter model: up to 15 IQ7 units, 12 IQ7+, 11 IQ7X, 10 IQ7A, 11 IQ8MC, 10 IQ8AC, 9 IQ8HC, 9 IQ8X, or 7 IQ8P microinverters per relay.
Can more than one Q Relay be used in a single system?
Yes — larger arrays can use multiple Q Relays, up to a system limit of four active Q Relay devices.
Is the Q Relay compatible with Enphase IQ Batteries?
Yes, the Q Relay provides the same physical disconnection function for Enphase IQ Battery installations as it does for microinverter-only systems, isolating the whole AC-coupled system during a grid fault.
Does the Q Relay need to be installed by a qualified electrician?
Yes. Installation and wiring must be carried out by a qualified electrician in line with BS 7671 and the Enphase installation manual, with the mains supply isolated before any connections are made.
What is the difference between this relay and the three-phase version?
This is the single-phase variant (Q-RELAY-1P-INT) for standard UK domestic installations. A separate three-phase Q Relay exists for commercial and three-phase supply installations and is not interchangeable with this unit.
