Motor Thermal Protection; High Voltage Connections - KEB Combivert F5 series Instruction Manual

1.5.6 Motor Thermal Protection

The F5 series inverters by default provide motor overload protection at 130% of the
inverter's UL rated current.
The F5 series inverters are classified as a UL approved solid state overload protection
device. It is necessary to activate the function in the software of the inverter. The function
meets the requirements set forth in VDE 0660 Part 104, UL508C section 42, and NEC
430 part C. See parameters dr.11, dr.12 and Pn.14 in the application mode for
adjustment.
Overload protection using a normally closed contact (min. rating 15V 6mA) or PTC type
sensor is also available using terminals T1 and T2. This function also must be activated
by the software of the inverter. See parameters CP.28 or Pn.10.
In general, overload protection through current sensing does not always provide
protection against overheating at low speeds; reduced fan cooling. Therefore it is
recommended that a motor winding sensor be used in applications requiring
prolonged operation at low motor speeds.

1.5.7 High Voltage Connections

Always note inverter voltage, select appropriate over current protection devices, select
disconnect device, and select proper wire size before beginning the wiring process. Wire
the inverter according to NEC Class 1 requirements.
The correct wire gauge for each size inverter can be selected from the charts on pages
15-20. Always use UL listed and CSA approved wire. The wire gauge is based on the
recomended fuse rating for the inverter and a minimum of 75°C insulation rating. Use
copper wire only. If a lower rated fuse is selected, then it may be possible to use a smaller
gauge wire. Use 300V rated wire with 230V systems and 600V rated wire with 460V
systems.
The terminal tightening torque can be found for each unit in the same tables.
To prevent coupling high frequency noise, the following wires must be spatially separated
from each other a minimum distance of 8 inches (20 cm)when they are laid parallel to
each other :
- AC supply power and motor lines not connected to inverters
- motor lines connected to inverters
- control and data lines ( low-voltage level < 48 V )
When using KEBCO EMI filters, use only the wire provided with the filter to connect the
filter to the inverter. Do not add additional wire between the filter and the inverter as this
will have a negative effect on the operation of the filter.
General
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