Danfoss VLT Series Design Manual page 101

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VLT HVAC Drive Design Guide
5.4.4. Relay Output
Relay 1
•
•
•
Relay 2
•
•
•
Relay 1 and relay 2 are programmed in par.
5-40, 5-41, and 5-42.
Additional relay outputs by using option mod-
ule MCB 105.
5.4.5. Parallel Connection of Motors
The frequency converter can control several
parallel-connected motors. The total current
consumption of the motors must not exceed
the rated output current I
converter.
Problems may arise at start and at low RPM
values if motor sizes are widely different be-
cause small motors' relatively high ohmic re-
sistance in the stator calls for a higher voltage
at start and at low RPM values.
The electronic thermal relay (ETR) of the fre-
quency converter cannot be used as motor
protection for the individual motor of systems
with parallel-connected motors. Provide fur-
ther motor protection by e.g. thermistors in
each motor or individual thermal relays. (Cir-
cuit breakers are not suitable as protection).
Terminal 01: common
Terminal 02: normal open 240 V AC
Terminal 03: normal closed 240 V AC
Terminal 04: common
Terminal 05: normal open 400 V AC
Terminal 06: normal closed 240 V AC
for the frequency
INV
NB!
When motors are connected in
Automatic
parallel, par. 1-02
Motor Adaptation (AMA)
be used.
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MG.11.B2.02 - VLT is a registered Danfoss trademark
cannot
5. How to Install
5
101