Recora Neptune NF-2 Foot Switch - Manual (Page 11)

Trouble Shooting a Switchmat System
All Switchmats are wired in series. Therefore, if any Switchmat in the system is shorting
out, the technician will not be able to tell which Switchmat has failed. In order to
determine which Switchmat has failed, the technician has to electrically disconnect each
Switchmat (all four wires) and test it independently of the system. Once the Switchmat is
disconnected a simple resistance check can be done to determine if the Switchmat is
operating properly. A properly functioning Switchmat will show infinite resistance when
no weight is on the Switchmat and 5
Ω or less when a person is standing on the
Switchmat. If the Switchmat reads 5 Ω or less without any weight on the Switchmat, it is
shorted and must be replaced. If the Switchmat reads ∞ Ω with the operator standing on
the Switchmat it is open. An open Switchmat is very unusual, carefully inspect the wire
for a break or where a screw has gone through the wire. If no broken wire is found
check your meter leads.
OHM Meter
OHM Meter
∞ ο ∞ ο
Not Not
Connected Connected
A B A B A B A B
A B
No Weight On Mat Operator on Safety Mat
1 meter lead connected to A 1 meter lead connected to A
2nd meter lead connected to B 2nd meter lead connected to B
TIP: A careful visual inspection of the Switchmat surface for dents or deformities may
lead the technician to the faulty Switchmat without having to take apart the entire
system. The most common cause of Switchmat failure is due to the corner of a
heavy object being dropped on the Switchmat, this dents the electrode and causes
the Switchmat to short out.
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