APG KA Cable Suspended user manual - Manual (Page 16)

KA Series Rev. A2, 12/08
16
Automation Products Group, Inc.
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their motors. These allow the KA fl oat switches to be connected directly. If
contactors are not provided, the contact ratings needed to start and stop
a pump should be approached with caution: when pump motors start and
stop, they can produce a momentary surge current several times greater
than the steady running current. Suppliers of the relays and contactors
usually provide maximum ratings for their contacts in terms of allowable
pump motor horsepower fi gures. If there are any concerns in this regard,
consult our Applications Engineering Department for advice.
• Verifying Operation
KA fl oat switches are highly reliable. However, if a check on the operation
of a particular switch is needed, it is fi rst necessary to ascertain where the
bias weight is located in order to fi nd the top point when the fl oat is in
the liquid. A good way to do this is to put the fl oat switch on a fl at surface
so that it can roll freely to the working orientation (just like it does in the
liquid). A continuity meter should then be attached to the circuit to be
tested. Testing is then performed by tilting the fl oat up and down in the
vertical plan determined by the working orientation. At the appropriate
angle, the switch circuit being tested should open or close.
• Valuable Tips
1. Do not be concerned if you hear a clacking sound when the fl oat is
shaken — it is only the microswitch acting. It is extremely unusual to
fi nd any leakage in these fl oats.
2. Do not put the full line power voltage across a contact without a load
attached. Shorting out the power across the microswitch will destroy it.
3. Do not tether the fl oats tightly on a short cable or make them jiggle
and dance in a high pressure washdown hose stream. The continuous
fl exing at a particular point in the cable will break the wires.