The 7SN8D-Q indoor high voltage live display device (VPIS – Voltage Presence Indicating System) is an advanced safety indicator manufactured by Xizi Energy, designed for medium voltage indoor switchgear.
Unlike standard T-type indicators, the Q-type (7SN8D-Q) integrates a heavy-duty interlock output (5A/250VAC) , making it suitable for forced locking applications such as electromagnetic lock control, cabinet door interlocking, and earthing switch prevention.
Need bulk pricing, custom labeling, or export support for the 7SN8D-Q? Send your cabinet voltage, sensor specifications, and order quantity – we will reply within 24 hours.
The 7SN8D-Q provides a 5A/250VAC relay contact output (terminals: B / A / PE). When any phase (L1/L2/L3) is detected as live, the interlock output activates to lock earthing switches, cabinet doors, or circuit breaker operating mechanisms. When all phases are de-energized, the output releases to allow safe operation.
Unlike passive T-type units, the 7SN8D-Q requires AC 100V–240V external power (connected via ACL and ACN terminals). This enables reliable interlock switching even under low primary voltage signal conditions.
Clear L1 (yellow), L2 (green), and L3 (red) LEDs indicate live status per phase. The panel also features dedicated “Power” (green) and “Lock” (red) status lights for immediate system awareness. The front-panel self-test button allows operators to manually verify the entire indication circuit and interlock logic before performing switching operations, eliminating hidden failure risks.
Embedded panel cutout dimensions follow industry standards, making the 7SN8D-Q a drop-in replacement for legacy DXN8D-Q, GSN-Q, and other Q-type live display units. Compatible with KYN28, XGN15, RM6 ring main units, GIS, and cabinets from Schneider, ABB, and Siemens.
Rated for 12kV systems (compatible with 7.2kV–40.5kV), with 20pF sensor capacitance matching. Suitable for 50Hz grids (60Hz available on request).
| Parameter | Specification |
|---|---|
| Model | 7SN8D-Q |
| Product Type | Q-Type Indoor VPIS with Forced Interlock Output |
| Rated System Voltage | 12kV (works with 7.2kV / 24kV / 40.5kV) |
| Matching Sensor Capacitance | 20pF |
| Auxiliary Power Supply | AC 100V–240V (terminals: ACL / ACN) |
| Interlock Output Contact Rating | 5A / 250VAC (resistive load) |
| Output Terminals | B / A / PE (normally open relay contact) |
| Indication | L1 (yellow), L2 (green), L3 (red) LEDs |
| Status Indicators | Power (green), Lock (red) |
| Self-Test Function | Front panel ON/OFF switch |
| Rated Frequency | 50Hz (60Hz customizable) |
| Operating Temperature | -25°C to +55°C |
| Relative Humidity | ≤95% (non-condensing) |
| Mounting Type | Embedded panel mount on switchgear door |
| Compliance Standard | DL/T 538 |
Connect ACL/ACN to AC 100V–240V to power the internal circuit and relay coil. Connect L1/L2/L3 terminals to matched capacitive voltage sensors installed on busbars or cable chambers.
When primary voltage is present, electrostatic signals trigger corresponding phase LEDs and activate the interlock output relay (B/A/PE). The red “Lock” LED illuminates to indicate active locking.
Toggle front ON/OFF switch to ON to simulate live status – all phase LEDs and the Lock LED should illuminate, and the relay output should change state. Toggle back to OFF for normal monitoring.
The 5A/250VAC output can directly control an electromagnetic lock, preventing earthing switch closure or cabinet door opening until all phases are de-energized.
The 7SN8D-Q is ideal for switchgear models that require forced interlocking between the live display and earthing switches or cabinet doors.
Factory HV rooms, chemical plants, steel mills, mining substations – any environment where misoperation prevention is critical.
Solar PV booster stations, wind farm switch rooms, energy storage BESS containers benefit from the Q-type’s reliable interlock output.
Grid distribution substations, hospitals, airports, data centers require high-safety VPIS with interlock functionality.
Indoor gas-insulated switchgear requiring interlock-capable VPIS with 5A relay output.
| Advantage | Description |
|---|---|
| Factory Direct | ISO-certified production, DL/T 538 compliant, suitable for utility tenders |
| Drop-In Replacement | 1:1 interchangeable with DXN8D-Q, GSN-Q – no cabinet modification needed |
| Heavy-Duty Interlock | 5A/250VAC relay output directly drives electromagnetic locks |
| Wide Power Range | AC 100–240V covers global auxiliary supply standards |
| Technical Support | Free wiring diagrams, installation guides, and remote consultation |
| OEM Customization | Custom labels, auxiliary voltages, and packaging available for bulk orders |
Every 7SN8D-Q unit is manufactured in an ISO-certified facility and passes DL/T 538 compliance testing, making it eligible for utility tenders and export projects.
The wide power supply range and multi-voltage compatibility make the 7SN8D-Q suitable for switchgear projects worldwide, from Japan (100V/60Hz) to Europe (240V/50Hz).
Xizi Energy offers custom labeling, branded packaging, and export documentation support for bulk orders, helping OEM distributors integrate the 7SN8D-Q into their product lines.
A: No. The Q-type requires AC 100V–240V to operate the internal relay and interlock logic. For self-powered applications, choose the 7SN8D-T.
A: The T-type provides visual voltage indication only and is passive (no external power required). The Q-type requires AC 100V–240V power and includes a 5A/250VAC interlock output for forced locking applications such as electromagnetic lock control.
A: The relay output is normally open (NO) . When any phase is live, the relay closes (output active). When all phases are de-energized, the relay opens (output inactive).
A: Yes. The panel cutout dimensions are identical, and the wiring scheme follows the same industry standard. Always verify terminal assignments with the included wiring diagram.
A: Stock units ship within 3–7 working days. Bulk orders take 10–15 working days. Contact us for export scheduling.
A: Yes. The panel cutout size, sensor interface, and wiring standards follow universal industry specifications, making it compatible with major international brands.
