Outdoor CT-PT Metering Units
MOBY Outdoor Combined CT-PT Metering Units integrate three Current Transformers (CT) and three Potential Transformers (PT)—or 2CT + 2PT for 3-wire systems—inside a single compact, oil-immersed steel tank for high-accuracy bulk power tariff metering up to 33 kV. Built strictly to State Electricity Board specifications (WBSEDCL, CESC, JBVNL, DVC, etc.), our units guarantee zero tamper vulnerability, Class 0.2S revenue precision, and decades of outdoor durability.
Comprehensive Technical Specifications
Detailed parameter ratings, insulation limits, standards compliance, and fabrication tolerances engineered for Outdoor CT-PT Metering Units.
| Technical Parameter | Engineering Specification | Compliance Standard / Condition |
|---|---|---|
| 🔷 General System & Rating Architecture | ||
| Nominal Voltage System | 11 kV or 33 kV, 3-Phase, 3-Wire or 4-Wire System | IS 2705 / IS 3156 |
| Highest System Voltage | 12 kV / 36 kV rms | Standard Rating |
| Rated Frequency | 50 Hz ± 3% | National Standard |
| Tank Architecture | Combined oil-immersed single mild steel tank housing both CTs and PTs | Monolithic Tank |
| Lightning Impulse Withstand (BIL) | 75 kVp (11kV) / 170 kVp (33kV) | Dielectric Test |
| One-Minute Power Frequency Withstand | 28 kV rms (11kV) / 70 kV rms (33kV) | Standard Test |
| Insulating Oil Quality | New uninhibited transformer mineral oil conforming to IS 335 (BDV > 60kV) | Dielectric Tested |
| 🔷 Current Transformer (CT) Section | ||
| Primary Current Ratings | 5/5A, 10/5A, 25/5A, 50/5A, 100/5A, 200/5A, 400/5A, 800/5A (Single or Dual Ratio) | Tailored to Sanctioned Load |
| Secondary Current | 5 Amperes (or 1 Ampere upon request) | Standard Metering |
| Accuracy Class | Class 0.2S or Class 0.5S (Revenue Tariff Grade) | High Precision |
| Rated Burden | 5 VA to 15 VA per phase | Low Burden High Precision |
| Short-Time Thermal Current | 13.1 kA / 18.4 kA / 25 kA for 1 or 3 Seconds | CPRI Tested |
| Instrument Security Factor (ISF) | ISF <= 5 (Protects delicate electronic energy meter from primary line surges) | Meter Protection |
| 🔷 Potential Transformer (PT) Section | ||
| Primary Voltage | 11000/√3 V (for 4-wire) or 11000 V (for 3-wire) / 33000/√3 V | Line Voltage |
| Secondary Voltage | 110/√3 V (for 4-wire) or 110 V (for 3-wire) | Standard Metering |
| Accuracy Class | Class 0.2 or Class 0.5 | High Precision |
| Rated Burden | 15 VA to 50 VA per phase | Class Burden |
| Voltage Factor | 1.2 Continuous / 1.5 or 1.9 for 30 Seconds | Overvoltage Withstand |
| 🔷 Mechanical & Sealing Security Details | ||
| Tank Construction | Heavy-gauge 3.15mm / 4.0mm MS sheet steel, fully seam welded and leak tested | Corrosion Resistant |
| Bushing Configuration | 6 High-Creepage Outdoor Glazed Porcelain Bushings (3 Primary Incomer / 3 Outgoing) | Brown Glaze |
| Secondary Metering Terminal Box | Double-door tamper-proof terminal box with dual padlock and wire-seal eyelets | DISCOM Anti-Theft |
| Fittings Included | Oil level sight gauge, silica gel dehydrating breather, drain valve, and lifting lugs | Complete Industrial |
Key Engineering & Operational Features
Why electrical consultants, industrial plants, and utility engineers specify MOBY Outdoor CT-PT Metering Units.
All-In-One Unified Footprint
Houses both CTs and PTs in a single oil tank, eliminating the need for 6 separate standalone instrument transformers and substantially simplifying pole or plinth mounting.
Guaranteed Tariff Revenue Accuracy
Engineered to deliver Class 0.2S and 0.5S accuracy curves strictly compliant with Indian Electricity Rules and DISCOM commercial billing standards.
Triple Anti-Theft Tamper Protection
Features a secondary terminal chamber protected by inner transparent acrylic cover, outer steel door with padlock shrouds, and dedicated holes for DISCOM lead seals.
Low Instrument Security Factor (ISF <= 5)
During external high-voltage line faults, the CT core safely saturates, preventing destructive fault currents from entering and frying the connected digital tri-vector meter.
Hermetic Leak-Proof Construction
Every tank undergoes 0.5 kg/cm² pressure testing for 24 hours at elevated temperatures to guarantee absolute oil tightness and zero oil weeping at gasket seams.
Individual Serial Number Calibration Certificate
Each unit is dispatched with comprehensive routine test certificates reporting precise ratio errors and phase angle displacements across 1% to 120% load.
Certified Quality & Factory Testing Standards
Every Outdoor CT-PT Metering Units 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:
Related Switchgears & Equipment
Explore complementary electrical power distribution and protection units manufactured by Moby.
Frequently Asked Questions
Authoritative engineering answers regarding voltage ratings, CPRI testing, custom SLD fabrication, and warranty for Outdoor CT-PT Metering Units.
What are the technical voltage and breaking ratings for MOBY Outdoor CT-PT Metering Units? +
Primary Parameter Ratings: MOBY Outdoor CT-PT Metering Units is engineered for rated voltage 11 kV / 22 kV / 33 kV and rated normal current Combined 3CT + 3PT or 2CT + 2PT in Single Tank. 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 CT-PT Metering Units CPRI tested and certified? +
Certification & Type Testing: Yes, MOBY Outdoor CT-PT Metering Units is IS 2705 / IS 3156 & DISCOM Approved. 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 CT-PT Metering Units? +
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 CT-PT Metering Units
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.