Avoid Unintended Start; Safe Stop Of The Adjustable Frequency Drive - Danfoss VLT Instruction Manual

VLT ® HVAC Drive Instruction Manual
1.1.6 Caution
The adjustable frequency drive DC link capacitors remain charged after power has been disconnected. To avoid an electrical shock hazard, disconnect
the adjustable frequency drive from line power before carrying out maintenance. Wait at least as follows before doing service on the adjustable
frequency drive:
Voltage
4 min.
200–240 V 1.1 - 3.7 kW
380–480 V 1.1 - 7.5 kW
1.5–10 hp [1.1–7.5
525–600 V
525–690 V
Be aware that there may be high voltage on the DC link even when the LEDs are turned off.
1.1.7 Installation at high altitudes (PELV)
At altitudes above 6,600 feet [2 km], please contact Danfoss regarding PELV.

1.1.8 Avoid unintended Start.

While the adjustable frequency drive is connected to line power, the motor can be started/stopped using digital commands, bus
commands, references or via the Local Control Panel.
• Disconnect the adjustable frequency drive from line power whenever personal safety considerations make it necessary to avoid an unintended
start.
• To avoid an unintended start, always activate the [OFF] key before changing parameters.
• Unless terminal 37 is turned off, an electronic fault, temporary overload, a fault in the line power supply or lost motor connection may cause a
stopped motor to start.

1.1.9 Safe Stop of the Adjustable Frequency Drive

For versions equipped with a Safe Stop terminal 37 input, the adjustable frequency drive can perform the safety function
Stop Category 0
draft CD IEC 61800-5-2) or
It is designed and deemed suitable for the requirements of Safety Category 3 in EN 954-1. This functionality is called Safe Stop. Prior to integrating and
using safe stop in an installation, a thorough risk analysis must be carried out on the installation in order to determine whether the safe stop functionality
and safety category are appropriate and sufficient. In order to install and use the safe stop function in accordance with the requirements of Safety Category
3 in EN 954-1, the related information and instructions of the
in the Instruction Manual are not sufficient for a correct and safe use of the safe stop functionality!
Caution
15 min.
7.5–60 hp [5.5–45 kW]
15–125 hp [11–90 kW]
kW]
60–125 hp [45–90 kW]
(as defined in EN 60204-1).
VLT HVAC Drive Design Guide
MG.11.A9.22 - VLT ® is a registered Danfoss trademark
Minimum Waiting Time
20 min. 30 min.
150–300 hp [110–200
kW]
150–350 hp [110–250 450–750 hp [315–560
kW] kW]
150–350 hp [110– 250 450–750 hp [315– 560
kW] kW]
must be followed! The information and instructions contained
1 Safety
40 min.
350–600 hp [250–450
kW]
850–1600 hp [630–
1200 kW]
Safe Torque Off
(as defined by
1-3
1