Danfoss Metasys N2 Programming Guide

1-77 Compressor Start Max Speed [RPM]
Range: Function:
the time where the motor is operated under
the minimum speed for the application. The
time without protection from the current limit
and torque limit must not exceed the value
set in parameter 1-79 Compressor Start Max
Time to Trip. If the value in
parameter 1-79 Compressor Start Max Time to
Trip is exceeds, the frequency converter trips
with alarm 18, Start failed.
When this function is activated to get a fast
start, parameter 1-86 Trip Speed Low [RPM] is
also activated to protect the application from
running below minimum motor speed, for
example when in current limit.
This function allows high starting torque and
use of a fast starting ramp. To ensure the
build-up of a high torque during the start,
various tricks can be done through clever use
of start delay/start speed/start current.
1-78 Compressor Start Max Speed [Hz]
Range: Function:
Size
related*
[ 0 -
par.
4-14
Hz]
NOTICE
Parameter 1-78 Compressor Start Max
Speed [Hz] has no have eect when
parameter 1-10 Motor Construction=[1]
PM, non-salient SPM.
The parameter enables high starting torque.
This is a function, where the current limit and
torque limit are ignored during start of the
motor. The time, from the start signal is given
until the speed exceeds the speed set in this
parameter, becomes a start-zone where the
current limit and motoric torque limit is set to
what is maximum possible for the frequency
converter/motor combination. This parameter
is normally set to the same value as
parameter 4-11 Motor Speed Low Limit [RPM].
When set to zero the function is inactive.
In this starting-zone, parameter 3-82 Starting
Ramp Up Time is active instead of
parameter 3-41 Ramp 1 Ramp Up Time to
ensure extra acceleration during the start, and
to minimise the time where the motor is
operated under the minimum speed for the
application. The time without protection from
the current limit and torque limit must not
exceed the value set in
parameter 1-79 Compressor Start Max Time to
Trip.I the value of parameter 1-79 Compressor
Start Max Time to Trip is exceeded, the
frequency converter trips with alarm 18 Start
failed.
1-78 Compressor Start Max Speed [Hz]
Range: Function:
When this function is activated to get a fast
start, parameter 1-86 Trip Speed Low [RPM] is
also activated to protect the application from
running below minimum motor speed, for
example when in current limit.
This function allows high starting torque and
use of a fast starting ramp. To ensure the
build-up of a high torque during the start,
various tricks can be done through clever use
of start delay/start speed/start current.
1-79 Compressor Start Max Time to Trip
Range: Function:
5 s* [0 -
10 s]
NOTICE
Parameter 1-79 Compressor Start Max Time to
Trip has no eect when parameter 1-10 Motor
Construction=[1] PM, non-salient SPM.
The time, from the start signal is given until the
speed exceeds the speed set in
parameter 1-77 Compressor Start Max Speed [RPM]
must not exceed the time set in the parameter. If
the time set is exceeded the frequency converter
trips with Alarm 18, Start failed.
Any time set in parameter 1-71 Start Delay for use of
a start function must be executed within the time
limit.
Parameter Descriptions Programming Guide
MG11CE02 Danfoss A/S © 03/2015 All rights reserved. 49
3 3

Danfoss Metasys N2 Specifications

General

Brand	Danfoss
Model	Metasys N2
Category	DC Drives
Language	English