Enclosure Design And Drive Ambient Temperature; Heatsink Fan Operation; Enclosing Standard Drive For High Environmental Protection - Emerson Unidrive M700 Installation Manual

3.6

Enclosure design and drive ambient temperature

Drive derating is required for operation in high ambient temperatures
Totally enclosing or through panel mounting the drive in either a sealed cabinet (no airflow) or in a
well ventilated cabinet makes a significant difference on drive cooling.
The chosen method affects the ambient temperature value (T
necessary derating to ensure sufficient cooling for the whole of the drive.
The ambient temperature for the four different combinations is defined below:
1. Totally enclosed with no air flow (<2 m/s) over the drive
T = T + 5 °C
rate int
2. Totally enclosed with air flow (>2 m/s) over the drive
T = T
rate int
3. Through panel mounted with no airflow (<2 m/s) over the drive
T = the greater of T
rate
4. Through panel mounted with air flow (>2 m/s) over the drive
T = the greater of T
rate
Where:
T = Temperature outside the cabinet
ext
T = Temperature inside the cabinet
int
= Temperature used to select current rating from tables in Chapter 5 Technical data on
T
rate
page 76.
3.7

Heatsink fan operation

The drive is ventilated by an internal heatsink mounted fan. The fan housing forms a baffle plate,
channelling the air through the heatsink chamber. Thus, regardless of mounting method (surface
mounting or through-panel mounting), the installing of additional baffle plates is not required.
Ensure the minimum clearances around the drive are maintained to allow air to flow freely.
The heatsink fan on all sizes is a variable speed fan. The drive controls the speed at which the fan
runs based on the temperature of the heatsink and the drive's thermal model system. The maximum
speed at which the fan operates can be limited in Pr 06.045. This could incur an output current
derating. Refer to section 3.13.1 Fan removal procedure on page 44 for information on fan removal.
3.8

Enclosing standard drive for high environmental protection

An explanation of environmental protection rating is provided in section 5.1.10 IP / UL Rating on
page 85.
The standard drive is rated to IP20 pollution degree 2 (dry, non-conductive contamination only)
(NEMA 1). However, it is possible to configure the drive to achieve IP65 rating (sizes 3 to 4) (NEMA
12) at the rear of the heatsink for through-panel mounting (some current derating is required). Refer
to Chapter 5 Technical data on page 76.
This allows the front of the drive, along with various switchgear, to be housed in a high IP enclosure
with the heatsink protruding through the panel to the external environment. Thus, the majority of the
heat generated by the drive is dissipated outside the enclosure maintaining a reduced temperature
inside the enclosure. This also relies on a good seal being made between the heatsink and the rear
of the enclosure using the gaskets provided.
32
+5 °C, or T
ext int
or T
ext int
Unidrive M/HS Frame 3 and 4 Power Installation Guide
) which should be used for any
rate
Issue Number: 3