© 2018 Littelfuse Fresh Water Pumping
14
Submersible Pumps – Optimized Protection
Littelfuse.com/Pump-Protection
Rapid Cycling
Rapid cycling is defined as more than 4 restarts in a 60-second
period. The units are capable of detecting a rapid-cycle condition
whether a control device, such as a pressure switch, is installed
before or after it. Upon detecting either form of rapid cycling,
the unit will lock-out, preventing damage to the pump. To reset
the unit, remove and re-apply power.
RAPID CYCLING (Line Side/Upstream)
Rapid cycling of the line side of the units may be caused by
several naturally occurring conditions which are indistinguishable
from true rapid cycling. For this reason, once tripped, the units
will wait 30 minutes and restart for protection. If any restart is
successful (pump runs for more than 1 minute), the rapid cycle
counter will reset to zero. If the unit encounters rapid cycle 4
times without a successful restart, the unit will lock-out and
require a manual reset. To reset, remove and re-apply power.
Note:
Turn the SENSITIVITY knob
completely
to the left
(counter-clockwise) or
completely
to the right (clockwise)
when directed.
To Enable Line-Side Rapid-Cycle Protection:
(to disable, follow the same procedure and replace the
jumper on the unit) (Insider models only)
1. Locate the Rapid-Cycle Jumper in the upper-right corner
behind the faceplate of the unit.
2. Remove the Rapid-Cycle Jumper. The jumper may be
removed before or after initial installation.
3. Save the removed jumper.
4. If the unit is not already installed, install as described in the
CONNECTIONS section of the unit’s install manual.
5. Re-apply power.
ABBREVIATED INSTALLATION INSTRUCTIONS
To Enable Rapid-Cycle Protection when a Control Device
is Installed BEFORE the unit:
(to disable, follow the
same procedure)
1. Remove power to the unit.
2. Set the RESTART DELAY/CALIBRATION knob to RESET and
the SENSITIVITY knob to the middle (12:00) position.
3. Apply power to the unit—the CAL LIGHT will turn on.
4. Turn the SENSITIVITY knob to the right—the CAL LIGHT
will turn off, RUN LIGHT will turn on.
5. Turn the SENSITIVITY knob to the left—both lights will
turn on.
6. Turn the SENSITIVITY knob right—left—right—left—right, in a
quick and smooth manner.
7. After 2 seconds, the CAL and RUN LIGHTS will blink once
indicating line side rapid-cycle protection has been enabled.
RAPID CYCLING (Load Side/Downstream)
Load side rapid cycling of the pump will immediately result in
a manual lock-out. The pump will not restart automatically. To
reset, remove and re-apply power.
Note:
Protection against rapid cycling of a control device
installed after the unit is always enabled. Disabling line side
detection will not disable load side detection.
