APG KA Cable Suspended user manual - Manual (Page 11)

Rev. A2, 12/08 KA Series
11
Automation Products Group, Inc.
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• Single Point with Timed Relay Control
There may be some situations where it is not possible to produce any form of
dual level control. In such cases an eff ective deadband can be produced with
a single level switch by using it in conjunction with a time delay relay. When
the switch operates, it turns on the relay which stays on for a predetermined
period so that the pump or valve operates for that set period each time that it
is turned ON.
• Emptying/Filling Pump Control Circuits
Simple Filling (Pump up) Control (Using Type 2L)
Simple Emptying (Pump down) Control with High Level Alarm
Note: In the above examples, the relay contact R1A is used to electrically latch the relay ON
in manual use. If the pump is manually started the fl oat switch will not turn OFF. (The relay/
contactor R1 used should be a DPST type with suitable ratings on one contact (R1B) able to carry
the voltage and current required by the pump motor horsepower rating. If the pump motor
requires three phase power, the relay contact R1B would have to comprise three poles of heavy
duty NO switches capable of carrying the pump motor power as well as there being an auxiliary
NO switch contact R1A for latching purposes. Heavy duty relay contactors of this type are readily
available at most electrical supply houses.
(Using Type 3HE plus manual override)