Outdoor Type CT and PT
MOBY Outdoor Current Transformers (CT) and Potential Transformers (PT) are manufactured for high-precision revenue metering and high-speed protection across utility distribution and transmission networks up to 132 kV. Hermetically sealed with oil impregnation and stainless steel expansion bellows, our instrument transformers offer exceptional accuracy (Class 0.2S / 0.5S for metering, 5P10 / 5P20 / PS class for relays) and withstand extreme lightning surges and short-circuit electrodynamic forces.
Comprehensive Technical Specifications
Detailed parameter ratings, insulation limits, standards compliance, and fabrication tolerances engineered for Outdoor Type CT and PT.
| Technical Parameter | Engineering Specification | Compliance Standard / Condition |
|---|---|---|
| 🔷 System Voltage & Insulation Levels | ||
| Rated Nominal Voltage | 11 kV / 22 kV / 33 kV / 66 kV / 132 kV | IS / IEC 61869 |
| Highest System Voltage (Um) | 12 kV / 24 kV / 36 kV / 72.5 kV / 145 kV | Standard Rating |
| Power Frequency Withstand Voltage | 28 kV (12kV) / 70 kV (36kV) / 275 kV rms (145kV) | Dielectric Test |
| Lightning Impulse Withstand (BIL) | 75 kVp (12kV) / 170 kVp (36kV) / 650 kVp (145kV) | IEC 60071-1 |
| Insulation Medium | High-grade mineral insulating oil under hermetic seal with nitrogen cushion / metallic bellows | BDV > 60 kV |
| Insulator Bushing | Brown glazed high-strength electrical porcelain or hydrophobic silicone composite insulator | Creepage >= 25–31 mm/kV |
| 🔷 Current Transformer (CT) Specifications | ||
| Primary Current Ratings | 10A, 25A, 50A, 100A, 200A, 400A, 600A, 800A, 1200A, 2000A (Single or Dual Ratio) | Wide Range |
| Secondary Current Ratings | 1 Ampere or 5 Amperes | Standard Output |
| Number of Cores | Up to 4 Cores (Core 1: Revenue Metering, Core 2: Overcurrent/EF, Core 3: Differential/PS class) | Independent Cores |
| Metering Accuracy Class | Class 0.2S, Class 0.5S, Class 0.2, Class 0.5 | IS 2705 / IEC 61869-2 |
| Protection Accuracy Class | 5P10, 5P20, 10P10, or Class PS (Knee Point Voltage & Excitation specified) | Non-Saturating |
| Short-Time Thermal Current (Ith) | Up to 40 kA for 1 or 3 Seconds (Dynamic rating Idyn = 2.5 × Ith) | Short-Circuit Proof |
| 🔷 Potential Transformer (PT) Specifications | ||
| Primary Voltage Ratings | 11000/√3 V, 22000/√3 V, 33000/√3 V, 132000/√3 V | Line-to-Ground |
| Secondary Voltage Ratings | 110/√3 V (Metering) / 110/3 V (Residual Voltage / Open Delta EF) | Standard Relaying |
| Number of Secondary Windings | Dual or Triple Windings for independent tariff metering and relay protection | Separated Circuits |
| Metering Accuracy Class | Class 0.2, Class 0.5, Class 1.0 (Burden up to 100 VA) | IS 3156 / IEC 61869-3 |
| Protection Accuracy Class | 3P, 6P (Burden up to 100 VA) | Residual EF relaying |
| Rated Voltage Factor | 1.2 Continuous / 1.5 or 1.9 for 30 Seconds | Emergency Over-Voltage |
| 🔷 Tank & Hardware Construction | ||
| Tank Material | Corrosion-resistant mild steel tank with hot-dip galvanized base | Hermetic Welded |
| Secondary Terminal Box | Weatherproof terminal box with cable gland and padlockable revenue seal cover | IP55 Ingress Rating |
| Grounding Terminal | Dual stainless steel earthing studs with M12 hardware | Low Impedance Ground |
Key Engineering & Operational Features
Why electrical consultants, industrial plants, and utility engineers specify MOBY Outdoor Type CT and PT.
Revenue-Grade High Metering Accuracy
Built with high-permeability toroidal nickel-iron / amorphous alloy cores, maintaining strict Class 0.2S and 0.5S ratio and phase angle accuracy even at 1% of rated current.
Non-Saturating Protection Cores
Protection cores (5P20 and Class PS) boast high knee-point voltages, ensuring faithful current reproduction during violent 40kA primary short-circuits without core saturation.
Hermetically Sealed Tank Technology
Stainless steel expansion bellows accommodate oil thermal volume fluctuations while completely isolating the dielectric mineral oil from atmospheric oxygen and moisture degradation.
Extreme Creepage Distance for Pollution
High-grade porcelain or silicone composite insulators provide 25mm/kV to 31mm/kV creepage distances, preventing flashovers in coastal sea salt and heavily polluted industrial zones.
Tamper-Proof Utility Sealing
Secondary terminal box incorporates transparent polycarbonate inner covers with provision for State Electricity Board wire-and-lead tamper-proof seals.
Hot-Dip Galvanized Weather Resistance
Exterior tanks, bases, and hardware undergo hot-dip galvanizing and multi-coat epoxy polyurethane finishing to withstand 25+ years of blistering sun and monsoon rain.
Certified Quality & Factory Testing Standards
Every Outdoor Type CT and PT is manufactured under strict ISO 9001:2008 quality control protocols and subjected to comprehensive routine testing at our Kolkata facility before dispatch.
Target Industrial Sectors & Deployment Scenarios
Engineered and tested for severe continuous operational duty across diverse sectors:
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Frequently Asked Questions
Authoritative engineering answers regarding voltage ratings, CPRI testing, custom SLD fabrication, and warranty for Outdoor Type CT and PT.
What are the technical voltage and breaking ratings for MOBY Outdoor Type CT and PT? +
Primary Parameter Ratings: MOBY Outdoor Type CT and PT is engineered for rated voltage 11 kV / 22 kV / 33 kV / 66 kV / 132 kV and rated normal current 10A to 2000A (Secondary 1A or 5A). It is built to withstand prospective short-circuit breaking currents up to 40 kA for 3 seconds, fully adhering to national and international power engineering guidelines.
Is MOBY Outdoor Type CT and PT CPRI tested and certified? +
Certification & Type Testing: Yes, MOBY Outdoor Type CT and PT is IS 2705 / IS 3156 & IEC 61869. All switchgears undergo comprehensive type-testing at the Central Power Research Institute (CPRI) and are routine tested (high-voltage dielectric withstand, contact resistance, and operational timing) at our ISO 9001:2008 certified Kolkata manufacturing facility prior to customer dispatch.
Can this equipment be customized according to our single-line diagram (SLD)? +
Custom Engineering Capabilities: Yes, Moby Electrotech specializes in custom-engineered electrical switchgear systems. Our Kolkata engineering team customizes incoming/outgoing feeder arrangements, CT/PT ratios, numerical protection relays, busbar ratings, enclosure dimensions, and ingress protection (IP42 to IP55) to match your exact site layout and SLD.
What is the standard warranty and quotation timeline for Outdoor Type CT and PT? +
Commercial Terms & Warranty: All MOBY equipment carries an engineering equipment warranty of 12 months from commissioning or 18 months from delivery. Technical commercial quotations are typically provided within 24 to 48 hours following single-line diagram (SLD) review.
Request Technical Quote for Outdoor Type CT and PT
Our senior electrical engineering team will review your single-line diagram (SLD), system voltage, and breaking requirements to provide a competitive quotation within 24 hours.