Indoor High Voltage Load Switch

Model:FZN25-12/FZR25-12D

Anqiang Power is a China manufacturer of indoor high voltage load switches. Our load switches feature a unique transmission structure design, where the arc extinguishing chamber only withstands high voltage during the closing and opening moments. Therefore, they are compact and lightweight, allowing for simultaneous operation of both the isolation contact and the arc extinguishing contact.

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Product Description

Anqiang Power presents the FZN25 and FZRN25 series, the next-generation indoor high voltage load switches for 12kV, 50Hz ring main units (RMU). Engineered with a direct-acting isolating contact linked to a vacuum interrupter, these switches deliver arc-free load making/breaking and robust short-circuit protection (for FZRN25). Whether you operate a utility substation, a wind power collection cabinet, or an industrial plant, our FZN25/FZRN25 series ensures reliable load control and safety.

FZN25 vs FZRN25: Which model fits your transformer and RMU application?

FZN25-12D/T630-20

Pure Load Switch

✓ Rated current: 630A
✓ Short-circuit breaking: None (no fuse)
✓ Best for: Cable loop switching, RMU main switch, frequent load cycles
✓ Typical use: Switching up to 1250kVA no-load transformer

FZRN25-12D/T125-31.5

Fuse-Combination Appliance

✓ Rated current: 125A (load) / 31.5kA (fault)
✓ Short-circuit breaking: 31.5kA (fuse SDLAJ-12)
✓ Best for: Transformer primary protection, fault isolation up to 31.5kA
✓ Transfer current: 2000A (smooth fuse-load switch coordination)

📍 Application & Selection Guide: Real-world scenarios

✅ Scenario 1: 12kV Ring Main Unit (RMU) as incoming/loop switch
Use FZN25 as the main load break switch. It handles 630A loop current, closing and opening the ring network. Integrated grounding switch provides safe earthing during maintenance.

✅ Scenario 2: Transformer feeder protection (e.g., 1000kVA, 1250kVA)
Choose FZRN25. The fuse (SDLAJ-12) will clear phase-to-phase and earth faults up to 31.5kA, while the vacuum load switch handles normal load current up to 125A. Perfect for wind/solar collection cabinets and compact substations.

✅ Scenario 3: No-load transformer switching (≤1250kVA)
Both FZN25 and FZRN25 can switch off no-load transformers thanks to the vacuum interrupter's high dielectric recovery. However, if you expect frequent short-circuit faults, always prefer FZRN25.

📋 Technical Specifications

Project Name	Parameter value
Project Name	FZN25-12D/T630-20	FZRN25-12D/T125-31.5
Rated voltage	12 KV
Rated frequency	50 HZ
Rated dynamic stability current	50 KA	—
Rated active load breaking current	630 A	125 A
Rated closed-loop breaking current	630 A	125 A
Rated cable charging and breaking current	10 A
Switching off an unloaded transformer (capacity)	1250 KVA
Rated short-circuit breaking current	—	31.5 KA
Rated transfer current	—	2000 A
Fuse model	—	SDLAJ-12
Impact energy output	—	2-5 J (Medium)
Rated short-circuit making current	50 KA
Rated dynamic stability current of the grounding switch	50 KA
Grounding switch 2S, thermal stable current	20 KA
Auxiliary circuit rated voltage	AC/DC220,110
Mechanical life	10,000 times

📐 Outline Drawings & Component Breakdown

FZRN25-12D – 1. Stationary contact, 2. Insulating cover, 3. Valve, 4. Frame, 5. Vacuum interrupter, 6. Conductive cylinder, 7. Fuse, 8. Energy storage shaft, 9. Grounding switch shaft, 10. Control panel.

FZN25-12D – same rugged construction, but without fuse holder. Direct-action isolating contact + vacuum interrupter ensures safe load switching.

Both models are compatible with KYN28-12, HXGN-12, and modular RMU enclosures. Optional electric motor mechanism available for remote SCADA integration. Contact us for CAD drawings (DXF/PDF).

🏭 Why Anqiang Power? – Your reliable partner for 12kV load switches

Factory direct – No middleman, better price and lead time (15-25 days).
Type tested – GB3804, IEC 60265-1, fully certified.
Customization ready – Electric operation, auxiliary switches, special interlocks.
Global references – Supplied to Southeast Asia, Middle East, Africa, South America.

📌 Real project references:

✅ Philippines – 200+ units of FZN25-12D/T630-20 supplied to a utility company in Metro Manila for RMU cabinet upgrades (2024–2025).

✅ Vietnam – 150 sets of FZRN25-12D/T125-31.5 deployed in solar farm collection cabinets (Binh Thuan province, 50MW project).

Frequently Asked Questions

Q1: What is the difference between FZN25 and FZRN25?
A: FZN25 is a pure load switch (max 630A, no internal fuse). FZRN25 is a fuse-combination device (load switch + fuse) that can interrupt short-circuit currents up to 31.5kA. Use FZRN25 when you need transformer short-circuit protection.

Q2: What does “rated transfer current” mean on FZRN25?
A: Transfer current (2000A) is the maximum current that the load switch can break when the fuse striker is activated. Above this value, the fuse alone interrupts the fault. Anqiang Power's FZRN25 ensures reliable coordination.

Q3: Can I install an electric operator on FZN25/FZRN25?
A: Yes, both support electric operation with AC/DC 110V or 220V. Perfect for remote control and SCADA systems.

Q4: What is the mechanical life of these load switches?
A: 10,000 operations under normal service conditions, thanks to the sealed vacuum interrupter and robust spring mechanism.

Q5: Do you provide samples before bulk order?
A: Absolutely. Pre-production samples are available with a lead time of 7-10 days. We also support factory witness tests.

📩 Need a customized solution or price list?

Tell us your rated current, operation type (manual/electric), and transformer capacity. We will reply within 24 hours.

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Email: sales@anqiangpower.com | WhatsApp:8615057324888

Hot Tags: Indoor High Voltage Load Switch Supplier, Indoor Load Switch Manufacturer, Custom Electrical Switch Wholesale

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Contact Info

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Address

Jinlu Industrial Zone, Beibaixiang Town, Yueqing City, Wenzhou City, Zhejiang Province, China
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E-mail

john@chaqele.com

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