Terminal number Terminal description Parameter number Factory default
1+2+3 Terminal 1+2+3-Relay1 5-40 No operation
4+5+6 Terminal 4+5+6-Relay2 5-40 No operation
12 Terminal 12 Supply - +24 V DC
13 Terminal 13 Supply - +24 V DC
18 Terminal 18 Digital Input 5-10 Start
19 Terminal 19 Digital Input 5-11 No operation
20 Terminal 20 - Common
27 Terminal 27 Digital Input/Output 5-12/5-30 Coast inverse
29 Terminal 29 Digital Input/Output 5-13/5-31 Jog
32 Terminal 32 Digital Input 5-14 No operation
33 Terminal 33 Digital Input 5-15 No operation
37 Terminal 37 Digital Input - Safe Stop
42 Terminal 42 Analog Output 6-50 Speed 0-HighLim
53 Terminal 53 Analog Input 3-15/6-1*/20-0* Reference
54 Terminal 54 Analog Input 3-15/6-2*/20-0* Feedback
Table 4.2: Terminal connections
Very long control cables and analog signals may, in rare cases
and depending on installation, result in 50/60 Hz earth loops
due to noise from mains supply cables.
If this occurs, break the screen or insert a 100 nF capacitor
between screen and chassis.
NOTE
The common of digital / analog inputs and outputs
should be connected to separate common terminals 20,
39, and 55. This will avoid ground current interference
among groups. For example, it avoids switching on
digital inputs disturbing analog inputs.
NOTE
Control cables must be screened/armoured.
4.1.3 Fuses
Branch Circuit Protection
In order to protect the installation against electrical and fire
hazard, all branch circuits in an installation, switch gear,
machines etc., must be short-circuit and over-current protec-
ted according to the national/international regulations.
Short-circuit protection:
The frequency converter must be protected against
short-circuit to avoid electrical or fire hazard. Danfoss
recommends using the fuses mentioned below to
protect service personnel and equipment in case of an
internal failure in the drive. The frequency converter
provides full short-circuit protection in case of a short-
circuit on the motor output.
Over-current protection
Provide overload protection to avoid fire hazard due to
overheating of the cables in the installation. Over
current protection must always be carried out according
to national regulations. The frequency converter is
equipped with an internal over current protection that
can be used for upstream overload protection (UL-
applications excluded). See par. 4-18 Current Limit in the
VLT HVAC Drive Programming Guide . Fuses must be
designed for protection in a circuit capable of supplying
a maximum of 100,000 A
rms
(symmetrical), 500 V/600 V
maximum.
Over-current protection
If UL/cUL is not to be complied with, Danfoss recommends
using the fuses mentioned in the table below, which will
ensure compliance with EN50178.
In case of malfunction, not following the recommendation
may result in unnecessary damage to the frequency converter.
Electrical Installation
VLT
®
HVAC Drive Operating Instructions
22 MG.11.AD.02 - VLT
®
is a registered Danfoss trademark
4