Illustration 3.11: Connection To 24 V Back-Up Supplier (A2-A3) - Danfoss VLT Series Design Manual

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VLT HVAC Drive Design Guide
3.8.8. 24 V Back-Up Option MCB 107 (Option D)
External 24 V DC Supply
An external 24 V DC supply can be installed for low-voltage supply to the control card and any
option card installed. This enables full operation of the LCP (including the parameter setting) and
fieldbusses without mains supplied to the power section.
External 24 V DC supply specification:
Input voltage range
Max. input current
Average input current for the frequency converter
Max cable length
Input capacitance load
Power-up delay
The inputs are protected.
Terminal numbers:
Follow these steps:
1.
2.
3.
4.
5.
6.
When MCB 107, 24 V back-up option is sup-
plying the control circuit, the internal 24 V
supply is automatically disconnected.
Terminal 35: - external 24 V DC supply.
Terminal 36: + external 24 V DC supply.
Remove the LCP or Blind Cover
Remove the Terminal Cover
Remove the Cable Decoupling Plate
and the plastic cover underneath
Insert the 24 V DC Back-up External
Supply Option in the Option Slot
Mount the Cable Decoupling Plate
Attach the Terminal Cover and the
LCP or Blind Cover.
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MG.11.B2.02 - VLT is a registered Danfoss trademark
3. VLT HVAC Selection
24 V DC ±15 % (max. 37 V in 10 s)
Illustration 3.11: Connection to 24 V back-up sup-
plier (A2-A3).
Illustration 3.12: Connection to 24 V back-up sup-
plier (A5-C2).
3
2.2 A
0.9 A
75 m
< 10 uF
< 0.6 s
73