Safety Precautions; Precautions For Use; Standard Operating Conditions - Mitsubishi Electric MDU-BN Instruction Manual

1. Safety Precautions

This Instruction Manual is meant mainly for those with specialized electrical knowledge who will use this product to manufacture assembled products,
perform electrical work, or conduct maintenance and inspections. This also includes those who will operate this product (the end user).
● When installing or removing MDU Breaker main unit and a Measuring Display Unit (MDU), first turn the host circuit breaker OFF and confirm that
no electricity is flowing.
● This product must be handled by someone with specialized knowledge.

2. Precautions for Use

Unless otherwise noted, the following terms in this Instruction Manual indicate the models shown below.
Molded Case Circuit Breaker (MCCB)

2.1 Standard operating conditions

● The standard operating conditions are described below. Be sure to use MDU Breaker within these conditions.
[1] Operating ambient temperature: -10 ° C to +40 ° C (must not exceed an average of +35 ° C within a 24 hour period)
[2] Ambient storage temperature: -25 ° C to +55 ° C (no condensation/freezing)
[3] Relative operating/storage humidity: 85% RH or less (no condensation)
[4] Altitude: 2,000 m or lower
[5] Operating/storage atmosphere: Must contain hardly any dust, smoke, corrosive gas, combustible gas, moisture, salt, etc.
● If the ambient temperature of MDU Breaker exceeds +40 ° C, use with a decreasing continuous load current.
Ambient temperature of +50 ° C: 0.9 times, ambient temperature of +60 ° C: 0.7 times
● Do not install in abnormal environments subject to high temperature, high humidity, dust, corrosive gas, vibration, impact, etc. Doing so may
cause electrical shock, fire, or may cause the product to stop working.
● Do not wipe the MDU Breaker main unit or MDU with thinner, detergent, or chemical cloth.
Doing so may fade printing, reduce insulation performance, or cause mold to form. Clean with air or by brushing.
● The case of the MDU may become discolored depending on the environment. However, this will not have any effect on performance.
● The LCD may have bright (always on) or dark (always off) pixels due to the characteristics of LCDs.
Because LCDs contain many display elements, there is no way to ensure that bright or dark pixels will never occur. Bright or dark pixels are not
defects in the product itself.
● The screen on the LCD may flicker due to the internal processing for refreshing, but this is not a trouble of the main body.
Caution
250 A frame
NF250-SEV with MDU,
NF250-HEV with MDU
Caution
400 A frame
NF400-SEW with MDU,
NF400-HEW with MDU
3
800 A frame
NF800-SEW with MDU,
NF800-HEW with MDU