2.2 Pre-Installation Check List
•
Before unpacking the adjustable frequency drive,
ensure the packaging is intact. If any damage has
occurred, immediately contact the shipping
company to claim the damage.
•
Before unpacking the adjustable frequency drive,
locate it as close as possible to the final instal-
lation site
•
Compare the model number on the nameplate to
what was ordered to verify the proper equipment
•
Ensure each of the following are rated for the
same voltage:
•
Line power
•
Adjustable frequency drive
•
Motor
•
Ensure that adjustable frequency drive output
current rating is equal to or greater than motor
full load current for peak motor performance
•
Motor size and adjustable frequency
drive power must match for proper
overload protection
•
If adjustable frequency drive rating is
less than motor, full motor output
cannot be achieved
2.3 Mechanical Installation
2.3.1 Cooling
•
Top and bottom clearance for air cooling must be
provided. Generally, 9 in [225 mm] is required.
•
Improper mounting can result in overheating and
reduced performance.
•
Derating for temperatures starting between 113
°
F
[45
°
C] and 122
°
F [50
°
C] and elevation 3,300 ft
[1,000 m] above sea level must be considered.
See
VLT
®
Design Guide
for detailed information.
The high power adjustable frequency drives utilize a
backchannel cooling concept that removes heatsink
cooling air, which carries approximately 90% of the heat
out of the back channel of the adjustable frequency drives.
The backchannel air can be redirected from the panel or
room using one of the kits below.
Duct cooling
A backchannel cooling kit is available to direct the heatsink
cooling air out of the panel when an IP20/chassis
adjustable frequency drives is installed in a Rittal enclosure.
Use of this kit reduces the heat in the panel and smaller
door fans can be specified on the enclosure.
Cooling out the back (top and bottom covers)
The backchannel cooling air can be ventilated out of the
room so that the heat from the backchannel is not
dissipated into the control room.
A door fan or fans are required on the enclosure to
remove the heat not contained in the backchannel of the
adjustable frequency drives and any additional losses
generated by other components inside the enclosure. The
total required air flow must be calculated so that the
appropriate fans can be selected.
Airflow
The necessary airflow over the heatsink must be ensured.
The flow rate is shown in
The fan runs for the following reasons:
•
AMA
•
DC Hold
•
Pre-Mag
•
DC Brake
•
60% of nominal current is exceeded
•
Specific heatsink temperature exceeded (power
size dependent)
•
Specific Power Card ambient temperature
exceeded (power size-dependent)
•
Specific Control Card ambient temperature
exceeded
Frame
Door fan/top fan
Heatsink fan
D1h/D3h
102 m
3
/hr (60 CFM)
420 m
3
/hr (250 CFM)
D2h/D4h
204 m
3
/hr (120 CFM)
840 m
3
/hr (500 CFM)
Table 2.3 Airflow
Installation
VLT
®
Refrigeration Drive Instruction Manual
2-2
MG16J122 - VLT
®
is a registered Danfoss trademark
2
2
