Decentral Solutions
If a motor features a Klixon thermal switch instead,
this can also be connected to the input. If
motors operate in parallel, the thermistors/thermal
switches can be connected in series (total
resistance lower than 3 k
).
-
Thermal load calculation (ETR - Electronic
Thermal Relay), based on present load and
time. This is compared with the rated motor
current I
M,N
and rated motor frequency f
M,N
.
The calculations take into account the need for
lower loading at low speeds due to the motor
’
s
internal ventilation being reduced.
ETR functions 1-4 correspond to Setup 1-4. ETR
functions 1-4 do not begin to calculate the load until
you switch to the Setup in which they have been
selected. This means that you can use the ETR function
even when changing between two or more motors.
Description of choice:
Select
No protection
[0] if you do not want a warning
or trip when a motor is overloaded.
Select
Thermistor warning
[1] if you want a warning
when the connected thermistor becomes too hot.
Select
Thermistor trip
[2] if you want a trip when the
connected thermistor becomes too hot.
Select
ETR warning
if you want a warning when the
motor is overloaded according to the calculations.
You can also program the variable frequency drive to
give a warning signal via the digital output.
Select
ETR Trip
if you want a trip when the motor is
overloaded according to the calculations.
Select
ETR warning 1-4
if you want a warning when
the motor is overloaded according to the calculations.
You can also program the variable frequency drive to
give a warning signal via one of the digital outputs.
Select
ETR Trip 1-4
if you want a trip when the motor
is overloaded according to the calculations.
NOTE
This function cannot protect the individual
motors in the case of motors linked in parallel.
130 Start frequency
(START FREQUENCY)
Value:
0.0 - 10.0 Hz
✭
0.0 Hz
Function:
The start frequency is active for the time set in
parameter 120
Start delay
, after a start command.
The output frequency will
’
jump
’
to the next preset
frequency. Certain motors, such as conical anchor
motors, need an extra voltage/start frequency
(boost) at start to disengage the mechanical brake.
To achieve this parameters 130
Start frequency
and 131
Initial voltage
are used.
Description of choice:
Set the required start frequency. It is a precondition
that parameter 121
Start function
, is set to
Start frequency/voltage clockwise
[3] or
Start
frequency voltage in reference direction
[4] and
that in parameter 120
Start delay
a time is set
and a reference signal is present.
NOTE
If parameter 123 is set higher than parameter
130, the start delay function (parameter
120 and 121) will be skipped.
✭
= factory setting. () = display text [] = value for use in communication via serial communication port
MG.90.F2.22 - VLT is a registered Danfoss trademark
114