Overview

This document provides detailed technical specifications and mechanical dimensions for Meccalte spa's range of 3-phase transformers and related electrical equipment. It includes electrical characteristics, power ratings, efficiency data, mechanical protection classes, noise levels, and dimensional data for various transformer models.

Electrical Characteristics

The transformers operate at multiple voltage levels including 115/200/230/400V and 138/240/277/480V, with power factors typically at 0.8. Power ratings range from approximately 5 kVA up to 38.4 kVA depending on the model and configuration.

Two insulation classes are specified: Class H and Class F, with Class H generally supporting higher temperature ratings. Efficiency percentages vary by model and class, typically ranging from about 78% to 87.5%.

Transformer Types and Power Ratings

• Models NPE 31-A/2 through NPE 31-F/2 cover power ratings from 8 kVA to 32 kVA with efficiencies between 81% and 86%.
• Models NPE 31-A/4 through NPE 31-F/4 include similar power ranges with slight variations in efficiency and noise levels.
• Single-phase configurations are available with dedicated windings or reconnected windings, supporting power ratings from 5.3 kVA to 25.5 kVA.
• Additional models such as NPE 32-A/4 through NPE 32-F/4 provide power ratings from 6 kVA to 22.6 kVA with efficiencies around 79% to 84%.

Mechanical and Acoustic Data

Weight and noise levels are provided for each model, with weights ranging from approximately 13 kg to over 130 kg depending on the transformer size. Noise levels at 50 Hz and 60 Hz operation are typically between 75 dB(A) and 91 dB(A).

Air volume flow rates for cooling are specified around 13 to 15 m3/min, ensuring adequate thermal management.

Protection and Accessories

Mechanical protection classes include IP21, IP23, and IP45, indicating varying degrees of enclosure protection against dust and water ingress.

Thermal protection devices such as PTC and PT100 sensors are standard or optional depending on the model. Regulators like UVR6 and bimetallic devices (DSR) are also mentioned as accessories.

Mechanical Dimensions and Mounting

Detailed dimensional data are provided for transformer mounting, including flange sizes, bolt hole counts, and coupling dimensions. Key dimensions include flange diameters (e.g., 356 mm to 490 mm), bolt hole counts (8 to 12 holes), and coupling sizes.

Angles for mounting flanges and couplings are specified (commonly 30° or 45°), facilitating proper installation alignment.

Summary of Critical Parameters

• Voltage Ratings: 115/200/230/400V and 138/240/277/480V
• Power Ratings: 5.3 kVA to 38.4 kVA
• Efficiency: 78% to 87.5% depending on class and model
• Insulation Classes: Class H and Class F
• Noise Levels: 75 dB(A) to 91 dB(A)
• Protection Classes: IP21, IP23, IP45
• Cooling Air Volume: Approx. 13 to 15 m3/min
• Mechanical Dimensions: Flange diameters 356-490 mm, bolt holes 8-12, coupling sizes detailed

Recommendations and Best Practices

• Select transformer models based on required power rating and voltage compatibility.
• Consider insulation class based on operating temperature and environmental conditions.
• Ensure proper mechanical protection class is chosen to match installation environment.
• Use specified thermal protection devices to prevent overheating.
• Follow detailed mechanical dimension specifications for mounting and coupling to ensure secure installation.