Metalarm
™
Series 3500 Metal Detectors
9
FIGURE 4
User supplied stainless steel “L” brackets are
suggested for securing the search coil assembly to
the conveyor. Brackets should be fitted to the coil. The
area for this purpose is shown on the coil assembly
drawing. (See Figure 4)
The search coil should then be bolted to the conveyor
frame so that the coil socket is on the opposite side of
the conveyor frame from any heavy-duty cables
or wiring.
Fit the top search coil section and bolt it in place.
A recommended idler spacing of 48"- 60" should apply
to the infeed and outfeed idlers adjacent to the search
coil. An idler isolation kit is recommended and may
be purchased from the factory. The idler isolation kit
provides suitable materials to electrically insulate the
idlers from the conveyor frame. Insulating the idlers
directly adjacent to each side of the search coil will help
to alleviate any possible false tripping. Electrical loops
can be created from the metal detectors field in relation
to the surrounding metal. The idlers, either side of the
search coil, should be checked to see that all nuts and
bolts are tight.
In the case of series connection, connect the lower
coil using the short length of cable provided to the
unmarked socket on the top coil. The cable to connect
the search coil to the control unit should be connected
to the socket marked ‘CU’ on the top search coil. In
the case of transmit/receive mode operation, both coils
are connected directly to the control unit.
In both cases make sure the cables are secured to the
conveyor frame and protected to prevent them
being damaged.
The search coil coax cable must not cross directly
under the search coil, as this may cause false tripping
to occur. The cable should be replaced should any
nicks in its outer cover occur.
If standard metal conduit must be used be used to
protect the coil cable(s), separate conduits must be
used for each cable; receiver and transmitter. If a clip
detector is required, the cable may be run in the same
conduit as the receiver or transmitter coil.