470
Dry Run Time Out
(DRY RUN TIME OUT)
Value:
5-30 sec.
31 = OFF
Function:
If the power is below the no/low flow power curve, run-
ning at max speed for the time set in this parameter,
the frequency converter will trip on Alarm 75: Dry run.
In open loop operation the maximum speed does not
necessarily need to be reached before tripping.
Description of choice:
Set the value to obtain the desired delay before trip-
ping. Manual or automatic restart can be programmed
in parameter 405
Reset function
and 406
automatic re-
start time
.
The value 30 disables Dry run detection.
471
Dry Run Interlock Timer
(Dry run int time)
Value:
0.5-60 min.
30 min.
Function:
This timer determines when a trip due to dry run can
be automatically reset. When the timer expires, the
automatic reset of the trip can automatically restart the
frequency converter again.
Description of choice:
Parameter 406
Automatic restart time
still determines
how frequent an attempt to reset a trip will be per-
formed. If for instance parameter 406
Automatic restart
time
is set to 10 sec. and parameter 405
Reset func-
tion
is set to Automatic Reset x10 the frequency con-
verter will attempt to reset the trip 10 times within 100
seconds. If parameter 471 is set to 30 min. the fre-
quency converter will consequently not be able to
perform automatic reset of dry run trip and will need a
manual reset.
484
Initial ramp
(INITIAL RAMP)
Value:
OFF/000.1s - 360.0 s
OFF
Function:
Allows the motor/equipment to be brought up to mini-
mum speed (frequency) at a rate different than the
normal Ramp-Up rate (param. 207).
Description of choice:
As an example, vertical pumps and other equipment
often have a requirement to not operate below a min-
imum speed any longer than necessary. Damage and
excessive wear can occur when operating below min-
imum speed (frequency) for too long a period of time.
The Initial Ramp is used to quickly accelerate the mo-
tor/equipment to minimum speed at which point, the
normal Ramp-Up rate (parameter 207) is made active.
The range of adjustment of the Initial Ramp is from
000.1 second to 360.0 seconds; adjustable in 0.1 sec-
ond increments. If this parameter is set to 000.0, OFF
is displayed in this parameter, the Initial Ramp is not
active, and the normal Ramp-Up is active.
Fill Mode
Fill Mode eliminates the occurrence of water hammer
associated with the rapid exhausting of air from piping
systems (such as Irrigation systems).
The frequency converter, set for Closed Loop opera-
tion uses an adjustable Fill Rate, a "Filled Pressure"
setpoint, an operating pressure setpoint, and a pres-
sure feedback.
Fill Mode is available when:
•
The VLT 2800 drive is in
Closed Loop
mode
(parameter 100).
•
Parameter 485 is
not 0
•
Parameter 437 is set to
NORMAL
After a start command, Fill Mode operation begins
when the frequency converter reaches minimum fre-
quency - set in parameter 201.
VLT
®
2800 Series
= factory setting, () = display text, [] = value for use in communication via serial communication port
56
MG.27.A2.02 - VLT
®
is a registered Danfoss trademark
Summary of Contents for VLT 2800 Series
Page 1: ...VLT 2800 MG27A202 VLT 2800 Operating Instructions Operating Instructions...
Page 62: ...192H4893 VLT 2800 Series MG 27 A2 02 VLT is a registered Danfoss trademark 61 Installation...
Page 76: ...VLT 2800 Series MG 27 A2 02 VLT is a registered Danfoss trademark 75 All about VLT 2800...
Page 77: ...VLT 2800 Series 76 MG 27 A2 02 VLT is a registered Danfoss trademark...
Page 103: ......
