68 • Control Keypad
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STOP PARAMETERS
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Displays in MINIMIZED MODE and MAXIMIZED MODE
(refer to section
6.4.1 page 40 for changing mode)
Display and Default
Values
Range Description
COAST DOWN DELAY
OFF
OFF, 10 –
3600 Sec.
Sets an Off delay timer that prevents the HRVS-DN to start
before the COAST DOWN DELAY time has elapsed.
When COAST DOWN DELAY is set to OFF:
If start command is initiated momentarily (via push button,
for example, to terminal 6 of the control module) before 3
seconds after stop are elapsed, it is ignored.
If start command is initiated and maintained (via closing a
switch, for example, to terminal 6 of the control module), start
occurs after 3 seconds (from stop) are elapsed.
When COAST DOWN DELAY is set to a value (10-3600
seconds):
If start command is initiated momentarily (via push button,
for example, to terminal 6 of the control module ) before 3
seconds after stop are elapsed, it is ignored (same as if COAST
DOWN DELAY is set to OFF).
If start command is initiated and maintained or if pressed
after 3 seconds and before the set time of COAST DOWN
DELAY, the HRVSDN trips (same as for TOO MANY STARTS),
displaying a fault message COAST DOWN TIME.
Reset is possible immediately.
STORE ENABLE
STOP PARAMETERS
Same as STORE ENABLE MAIN & PROTECT page 57.
7.8.4.1
Soft Stop Parameters
SOFT STOP initiation opens the End of Acceleration contact and opens the Bypass Contactor. Load will be
transferred to the HRVS-DN thyristors and voltage begins to ramp down.
The HRVS-DN incorporates 5 stopping curves that enable you to select the suitable torque curve:
SOFT STOP CURVE 1
– Standard Curve (Default) – voltage is linearly reduced from nominal to zero.
The most stable and suitable curve for preventing prolonged stopping and motor overheating.
SOFT STOP CURVE 2, 3, 4 Pump Control
– In some pump applications, when pumping to higher elevation a
considerable part of the torque is constant and does not decrease with speed.
It may happen that during the deceleration process when voltage decreases the motor torque abruptly falls
below load torque (instead of smoothly decreasing speed to zero), thus closing the valve and causing water
hammer.
Curves 2, 3 and 4 eliminate the water hammer phenomenon. In pump applications the load torque decreases
in square relation to the speed, thus correcting control of voltage to reduce torque adequately and to smooth
deceleration to a stop.
Note
:
It is recommended that SOFT STOP CURVE 1 be used for all standard applications (not pumps).
To reduce water hammer, select SOFT STOP CURVE 2, then 3, then 4 in that order.
