8 Considerations During Installation
8.1 Operating Environment
For specifications regarding ambient conditions, see
chapter 6.9 Ambient Conditions for Drive Modules
NOTICE
CONDENSATION
Moisture can condense on the electronic components
and cause short circuits. Avoid installation in areas
subject to frost. Install a cabinet heater when the unit is
colder than the ambient air. Operating in stand-by mode
reduces the risk of condensation as long as the power
dissipation keeps the circuitry free of moisture.
Aggressive gases, such as hydrogen sulphide, chlorine, or
ammonia can damage the electrical and mechanical
components. The VLT
®
Parallel Drive Modules uses
conformal-coated circuit boards to reduce the effects of
aggressive gases. For conformal-coating class specifications
and ratings, see
chapter 6.9 Ambient Conditions for Drive
.
When installing the unit in dusty environments, pay
attention to the following:
Periodic maintenance
When dust accumulates on electronic components, it acts
as a layer of insulation. This layer reduces the cooling
capacity of the components, and the components become
warmer. The hotter environment decreases the life of the
electronic components.
Keep the heat sink and fans free from dust build-up. For
more service and maintenance information, refer to
VLT
®
Parallel Drive Modules Service Manual
.
Cooling fans
Fans provide airflow to cool the unit. When fans are
exposed to dusty environments, the dust can damage the
fan bearings and cause premature fan failure.
WARNING
EXPLOSIVE ATMOSPHERE
Do not install the frequency converter in a potentially
explosive atmosphere. Install the unit in a cabinet
outside of this area. Failure to follow this guideline
increases risk of death or serious injury.
Systems operated in potentially explosive atmospheres
must fulfill special conditions. EU Directive 94/9/EC (ATEX
95) classifies the operation of electronic devices in
potentially explosive atmospheres.
•
Class d specifies that if a spark occurs, it is
contained in a protected area.
•
Class e prohibits any occurrence of a spark.
Motors with class d protection
Does not require approval. Special wiring and containment
are required.
Motors with class e protection
When combined with an ATEX approved PTC monitoring
device like the VLT
®
PTC Thermistor Card MCB 112, instal-
lation does not need an individual approval from an
approbated organization.
Motors with class d/e protection
The motor itself has an e ignition protection class, while
the motor cabling and connection environment is in
compliance with the d classification. To attenuate the high
peak voltage, use a sine-wave filter at the VLT
®
Parallel
Drive Modules output.
When using the VLT
®
Parallel Drive Modules in a
potentially explosive atmosphere, use the following:
•
Motors with ignition protection class d or e.
•
PTC temperature sensor to monitor the motor
temperature.
•
Short motor cables.
•
Sine-wave output filters when shielded motor
cables are not used.
NOTICE
MOTOR THERMISTOR SENSOR MONITORING
VLT
®
AutomationDrive units with the MCB 112 option are
PTB-certified for potentially explosive atmospheres.
A frequency converter contains many mechanical and
electronic components, many of which are vulnerable to
environmental effects.
CAUTION
The frequency converter should not be installed in
environments with airborne liquids, particles, or gases
capable of affecting and damaging the electronic
components. Failure to take the necessary protective
measures increases the risk of stoppages, thus reducing
the life of the frequency converter.
Degree of protection as per IEC 60529
To prevent cross faults and short circuits between
terminals, connectors, tracks, and safety-related circuitry
caused by foreign objects, the Safe Torque Off (STO)
function must be installed and operated in an IP54 or
higher rated control cabinet (or equivalent environment).
Considerations During Insta...
Design Guide
MG37N102
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Summary of Contents for VLT 380-500 V
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