Overview
The JDZW-35R and JDZFW-35W2 are outdoor-type, epoxy resin cast voltage transformers designed for 35kV medium-voltage AC systems. These single-phase electromagnetic instruments provide galvanically isolated secondary voltage signals proportional to the primary system voltage, using a fully enclosed pillar-type construction with solid dielectric insulation.
Offering accuracy classes of 0.2 and 0.5, they support precision energy metering, relay protection, and grid monitoring applications in outdoor substations and switchyards. The units comply with international and national standards including IEC 61869-1/3, GB/T 20840.1/3, and JB/T 5277, ensuring reliable performance under continuous or transient overvoltage conditions.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| System voltage class | 35 kV (outdoor) |
| Rated frequency | 50 Hz or 60 Hz |
| Rated primary voltage | 35 kV / √3 (line-to-ground) |
| Rated secondary voltage | 100 V / √3 (standard); dual on JDZFW-35W2 |
| Accuracy classes | 0.2 / 0.5 |
| Rated burden | 30 VA, 50 VA, 80 VA per winding |
| Limit output capacity | 800 VA (JDZFW-35W2) / 1000 VA (JDZW-35R) |
| Burden power factor | cosφ = 0.8 (lagging) |
| Rated voltage factor | 1.2 Un continuous / 1.9 Un for 30 s |
| Insulation level (Um/Ud/Uac) | 40.5 / 95 / 200 kV |
| Applicable standards | IEC 61869-1/3; GB/T 20840.1/3; JB/T 5277 |
| Variants | JDZW-35R (single sec.) / JDZFW-35W2 (dual sec.) |
Construction
The transformers feature a pillar-type structure suitable for outdoor substation mounting, with a fully enclosed epoxy resin cast insulation system that ensures high resistance to moisture, UV radiation, contamination, and arc tracking. The core is built from laminated silicon steel for low losses and excellent linearity, while both primary and secondary windings carry a class H thermal rating. A weatherproof junction box with anti-theft provisions houses the terminals, and a robust steel channel base with a four-hole pattern allows flexible orientation during installation. The solid epoxy dielectric eliminates fire risk and oil-maintenance requirements, delivering long-term reliability in harsh environments.
Technical Parameters
Service Conditions
- Installation: Outdoor installation (IP-rated enclosure)
- Altitude: ≤ 1000 m (higher altitude requires derating or enhanced insulation specification)
- Ambient temperature: −25 °C to +40 °C
- Relative humidity: Daily average ≤ 95%, monthly average ≤ 90% (condensation permissible)
- Pollution level: Class II or higher per IEC 60815 (Class III/IV available for heavy pollution environments)
- Environmental conditions: UV exposure resistance; suitable for industrial, coastal, or high-pollution areas; no severe mechanical shock or vibration
Technical Parameters
The JDZW-35R and JDZFW-35W2 are outdoor cast-resin voltage transformers rated for 35 kV systems, designed for operation in ambient temperatures from −25 °C to +40 °C and altitudes up to 1000 m. They comply with IEC 61869-3 and GB/T 20840.3 standards, featuring dual-secondary configurations and accuracy classes suitable for both metering and protection applications.
| Type | Rated Ratio (kV) |
Accuracy
Class |
Burden (VA) |
Rated Output (VA) |
Rated Insulation Level (kV) |
|---|---|---|---|---|---|
| JDZW-35W2 | 35/0.1 | 0.2 | 30 | 1000 | 40.5/95/200 |
| 0.5 | 80 | ||||
| JDZFW-35W2 | 35/0.1/0.1 | 0.2 / 0.5 | 30/30 or 30/50 | 800 | 40.5/95/200 |
| 0.5 / 0.5 | 50/50 |
Installation & Wiring
Outline Dimensions
The dimensional drawing provides critical outline dimensions and mounting details for the JDZW-35R and JDZFW-35W2 outdoor epoxy-resin voltage transformers. The unit features a four-hole steel channel base allowing flexible installation orientation in any direction.
Selection & FAQs
Selection Guide
- Choose JDZW-35W2 for single-secondary applications serving unified metering or protection functions.
- Select JDZFW-35W2 when independent, galvanically isolated secondary windings are needed for separate metering and protection circuits.
- Specify accuracy class per winding: 0.2 class for revenue metering, 0.5 class for protection or general monitoring per IEC 61869-3.
- Define rated burden (30 VA, 50 VA, or 80 VA per winding) based on total connected load including meters, relays, instruments, and wiring losses at 100 V.
- Confirm insulation level (standard 40.5/95/200 kV or enhanced), pollution class (II, III, or IV), and altitude rating (≤1000 m or high-altitude) according to site conditions and grid requirements.
- Include special requirements at ordering stage—such as residual voltage windings, terminal arrangements, mounting details, documentation language, or certifications—for technical agreement prior to production.
Frequently Asked Questions
Q1: Can these 35kV voltage transformers be installed at 2000m altitude?
Standard models are rated for altitudes up to 1000m. For 2000m installations, enhanced insulation specifications or derating is required. Please contact our engineering team for altitude-specific adjustments.
Q2: Which accuracy class is suitable for 35kV protection and metering?
The JDZW-35R and JDZFW-35W2 feature a 0.2 accuracy class with a 30VA burden. This dual-secondary configuration supports precise metering and protection per IEC 61869-3. Specify your exact burden requirements during ordering.
Q3: Are these outdoor cast resin transformers resistant to heavy pollution?
Yes, they meet Class II pollution levels per IEC 60815. For coastal or heavy industrial areas, Class III or IV pollution resistance can be customized. Confirm your specific environmental conditions with our sales team.
Q4: What international standards do these 35kV voltage transformers comply with?
They fully comply with IEC 61869-3 and GB/T 20840.3 standards. Factory type tests and routine tests are conducted according to these specifications. Request the specific test certificates during the quotation phase.
Q5: How are the dual-secondary windings tested before factory shipment?
Each unit undergoes routine testing, including ratio, polarity, and insulation resistance checks. Specific short-circuit or thermal stability tests are subject to confirmation. Please provide your single-line diagram for detailed test planning.
Q6: Where is the JDZFW-35W2 model primarily applied in power systems?
It is an outdoor epoxy resin cast voltage transformer designed for 35kV power systems. It is primarily applied for voltage measurement and relay protection in outdoor substations. Contact us for dimensional drawings.