Siemens A1 User Manual
International English
Getting Started
MICROMASTER Applications Handbook
17
4
Getting Started with an Inverter
4.1
Mounting the Inverter
Mount the inverter using the mounting holes provided as described in the
Operating Instructions. Ensure the correct torque ratings for the fixing bolts are not
exceeded.
Operating Instructions. Ensure the correct torque ratings for the fixing bolts are not
exceeded.
The unit may be mounted horizontally or vertically without derating. Do not mount
the units upside down or sideways, as the fan cooling will oppose natural
convection cooling.
the units upside down or sideways, as the fan cooling will oppose natural
convection cooling.
4.2 Cooling
Many inverters will operate in a temperature of 50
° C without de-rating.
Make sure that the inlet and outlet ducts are not blocked, for example by cables.
It is very important to ensure that the maximum operating temperatures are not
exceeded inside a cubicle. When installing an inverter in a cabinet, it is necessary
to calculate the heat rise:
exceeded inside a cubicle. When installing an inverter in a cabinet, it is necessary
to calculate the heat rise:
1.
Calculate total heat loss (P
loss
) for all units inside the cabinet . Use manufacturers’ data or
assume 3% loss.
2.
For a sealed cabinet, calculate temperature rise using the formula:
T
rise
= Pl
oss
/(5.5 x A)
Where A is the total exposed area of the cabinet in square metres.
For a fan cooled cabinet, calculate temperature rise using the formula:
For a fan cooled cabinet, calculate temperature rise using the formula:
T
rise
= (0.053 x Pl
oss
)/F
Where F is the air flow in cubic metres /minute.
3.
Add the Temperature rise to the external ambient temperature. If this is greater than the
operating temperature of the drive, additional cooling will be needed, or the units must be
de-rated.
operating temperature of the drive, additional cooling will be needed, or the units must be
de-rated.
It will also be necessary to de-rate at altitudes above 1000 m. Typical de-rating is
as follows:
as follows:
2000 m
85% of full load rating.
3000 m
75% of full load rating.
4000 m
65% of full load rating.
For more information consult the inverter supplier.
4.3
Wiring up the Inverter
Warning
This Equipment must be Earthed
Note the warning guidelines in the Operating Instructions, and ensure all safety
regulations are complied with.
regulations are complied with.
Follow the wiring instructions in the Operating Instructions, including the EMC
guidelines.
guidelines.