Startup Assistant & Parameters 12-873AXD50000011888
Table 12-4 Level 1 Parameter Block Definitions
Block Title
Parameter (Number)
Selection (Value)
Descriptions
TRICKLE CURRENT Trickle current prevents rotation of fan during standby condition (anti wind mill feature). This can be caused
by exterior wind conditions or by adjacent tower airow that can act on the fan blades. Trickle current will
produce a low level dc voltage across the windings of the direct drive motor. The dc voltage when applied
to a permanent magnet motor will inhibit rotation of the fan blades. As a secondary benet the voltage will
produce enough heating in the motor windings to inhibit condensation in the motor caused by humidity.
Operation will be while the tower is in a power on but standby mode.
TRICKLE CURRENT ENABLE
(74.01)
Default: 0 (Disable)
Range: 0 - 2
0 (Disable) Disable trickle current.
1 (Enable) Enable trickle current.
2 (Fieldbus) Fieldbus CTD cmd Word bit 0
Software Enable (1) or Disable (0) trickle current parameter setting.
A hardware enable on DIO1 is also required to activate trickle current.
TRICKLE CURRENT LEVEL
(74.02)
Default: 100W
Range: 0 - 500W
The level of trickle current is determined by frame size of the motor and
input to the drive power level, no decimal required. Formula for how
current value is determined:
Frame Size Family Motor Wattage
FL2800 72
FL4400 119
FL5800 500
Trickle Current =
* Wattage
Setting is entered as a power level.
TRICKLE DELAY TIME (74.03)
Default: 1 Min
Range: 0 - 10 Min
The time delay before trickle current starts. This delay ensures the motor
has ramped down and stopped prior to trickle current beginning.
DE-ICE FUNCTION This is a cooling tower function to run at a low speed but in the opposite direction than standard. Primarily
this function is to prevent ice buildup in towers for colder climates. De-ice function consists of a setting for
the speed and a time value.
DE-ICE ENABLE (75.01) Default: 0 (Disable)
Range: 0 - 1
0 (Disable) Disable De-ice function
1 (Enable) Enable De-ice function
2 (Fieldbus) Fieldbus CTD cmd Word bit1
Software Enable (1) or Disable (0) De-ice function. A hardware enable on
DIO2 is also required to activate de-ice function.
DE-ICE SPEED (75.02) Default: 30%
Range: 0 - 100%
The minimum value should not be allowed to be programmed at less than
30% motor base speed.
DE-ICE RUN TIME (75.03) Default: 1 Min.
Range: 0 - 60 Mins.
Value of time to run in de-ice function when Software Enable is active, and
a hardware input is present. Drive will run at De-Ice function speed for the
set run time and then shut down.
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