
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 adjustable frequency drive 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
adjustable frequency drive 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 adjustable fre-
quency drive will attempt to reset the trip 10 times
within 100 seconds. If parameter 471 is set to 30 min.
the adjustable frequency drive 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:
For example, vertical pumps and other equipment of-
ten have a requirement to not operate below a mini-
mum speed any longer than necessary. Damage and
excessive wear can occur when operating below min-
imum speed (frequency) for too long. The initial ramp
is used to quickly accelerate the motor/equipment to
minimum speed at which point, the normal ramp-up
rate (parameter 207) is made active. The range of ad-
justment of the initial ramp is from 000.1 second to
360.0 seconds; it can be adjusted in 0.1 second incre-
ments. OFF is displayed in this parameter if it is set to
000.0, and 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 adjustable frequency drive, set for Closed Loop
operation uses an adjustable Fill Rate, a "Filled Pres-
sure" setpoint, an operating pressure setpoint, and a
pressure 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
VLT
®
2800 Series
= factory setting, () = display text, [] = value for use in communication via serial communication port
82
MG.27.A2.22 - VLT
®
is a registered Danfoss trademark