MDI METERS

MDI METERS

MDI-96(3)

MDI-72

Beemet maximum demand indicator meters indicate the thermal /time characteristics of load and help audit efficient use of transformer stations and LT distribution feeders. The dimensions comply with the requirements of DIN 43700 and scales with DIN 43802. The performance confirms to IS 1248-83/93. The cases are made of polycarbonate.

The instrument pointer is accompanied by a red slave pointer which is driven by the torque of a bimetallic movement. This slave pointer remains at the max reading position for a successive reading and has to be reset to its default position with the help of a knob.

In the three-pointer MDI meter, a moving iron movement is housed in addition to the bimetallic spring, which indicates instantaneous and maximum demand currents.

Salient Features

• Rugged movement ensures sustained accuracy and reliability.
• Reset knob is easily accessible.
• Square bezel permits edge to edge mounting, allowing maximum use of panel space.
• Interchangeable dial for range portability.
• Almost linear scale for MI dial in 3-pointer.                                               
• Clear scaling for easy reading.

General Specifications

Accuracy ±3.0% FSD (Bimetallic),   ±1.5% FSD (Moving Iron)
Measurable Quantities AC Current
Pointer deflection 0 - 90º
Frequency 45 – 60Hz
Thermal Time delay 8 or 15 minutes
Moving Iron Response Time ~2 seconds
Overload capacity According to IS: 1248 / IEC 51
Short duration 10 times for 5s: 1 overload
10 times for 0.5s: 9 overload
Continiously 1.2 times rated voltage or current
Power Consumption @1A <1.6VA (2-pointer), <2.5VA (3-pointer)
Power Consumption @5A <2.5VA (2-pointer), <3.4VA (3-pointer)
Ambient Temperature @ use 0 to 50°C
Operating Temperature -10 to 55°C
Storage Temperature -25 to 65°C
Relative Humidity < 75% annual average, non-condensing

Range Chart

Model Bimetallic Moving Iron For use on CT
MDI – 72, 96(3) 1A 1A __ / 1A
MDI – 72, 96(3) 5A 5A __ / 5A

Dimensions

PointersModel Dimensions (mm)
A B C D E Bimetallic Scale Moving Iron Scale Panel Cutout
Two Pointers MDI-72 72 66 53 67.3 5.5 61 68x68
MDI-96 96 90 53 91.5 5.5 97 92x92
Three Pointers MDI-72(3) 72 66 53 67.3 5.5 52 61 68x68
MDI-96(3) 96 90 53 91.5 5.5 71 97 92x92

Wiring Diagrams

With direct connection

With Current Transformer