Eriez 1250 ANALOG Manual

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MM-1250-ANALOG-C
Installation, Operation
and Maintenance
Instructions
ERIEZ MAGNETICS HEADQUARTERS: 2200 ASBURY ROAD, ERIE, PA 16506–1402 U.S.A.
WORLD AUTHORITY IN SEPARATION TECHNOLOGIES
TRAMP METAL
DETECTOR
MODEL 1250 ANALOG

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Introduction
This manual details the proper steps for installing,
operating and maintaining the Eriez Model 1250
Metal Detector.
Careful attention to these requirements will assure
the most efficient and dependable performance of
this equipment.
If there are any questions or comments about the
manual, please call Eriez at 814/835-6000 for Metal
Detector assistance.
©2004 ERIEZ MAGNETICS ALL RIGHTS RESERVED
CAUTION: Safety labels must be affixed to
this product. Should the safety label(s) be damaged,
dislodged or removed, contact Eriez for replacement.

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Table of Contents
ERIEZ MODEL 1250 METAL DETECTOR
PART I - OPERATION & DESCRIPTION .............................................................. 4
PART II - INSTALLATION ...................................................................................... 8
PART III - START-UP & CALIBRATION............................................................... 14
PART IV - SYSTEM PROGRAMMING ................................................................ 16
PART V - TROUBLESHOOTING......................................................................... 22
PART VI - MAINTENANCE.................................................................................. 27

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A. GENERAL
The Model 1250 provides protection to downstream
processing equipment by detecting the presence of
potentially damaging metal objects. It is specifically
designed for use on conveying systems in the food,
plastics, forest, agriculture, rubber, recycling and
mining industries.
The Detector makes use of the latest in solid state
technology, incorporating programmable logic
known as EPROM (Erasable Programmable Read
Only Memory). The design includes a number of
innovative features: self-test circuits that monitor
the performance of the detection circuitry; light
emitting diodes (L.E.D.’s) which indicate the status
of the test circuits; wide programming capability to
custom tailor the Detector to suit specific applica-
tion requirements; and solid state relays to provide
reliable arc-free switching.
B. METHOD OF OPERATION
During normal operation, the transmitter coil is
energized to produce a pulsed electromagnetic
signal. These signals produce a field that locally
permeates the conveyed material. A piece of metal
entering this field absorbs energy emitted from the
transmitter coil. The metal particle then releases the
energy and this change is detected by the receiver
coil. This technique provides optimum discrimination
between tramp metal and the conveyed material;
product effect is non-existent or minimal.
Having detected metal by a waveform change, the
signal generated is amplified and filtered. The sig-
nal is then compared to a threshold determined by
the size of metal that must be detected. When the
signal exceeds this threshold, the Detector, at the
appropriate time, triggers solid state relays. These
solid state relays in turn switch the line voltage
to the Detector’s output alarm terminals. Various
combinations of alarm horns, belt stop relays, alarm
beacons, etc., can then be activated by the switched
alarm outputs
The Detector is influenced only by change. There-
fore, stationary structural members, metal belt cores,
symmetrical idlers and other objects which do not
represent a moving mass to the field are not detect-
ed. Metal belt repair clips are passed by the unit with
an optional clip detector sensor and inhibitor circuit
which is properly adjusted to the clip signal.
C. PHYSICAL DESCRIPTION
MAIN CONTROL ENCLOSURE
This enclosure houses and protects the Electronic
and Interface Modules and also serves as a junc-
tion box for conduit and cables running to and from
the Detector. As standard, the control is housed in
a steel NEMA 4 enclosure. Other enclosures are
available as options.
Visible and accessible on the front panel are:
Power On/Off Switch, Green Power “ON” Indicator
Lamp, Red Trip Indicator Lamp that lights when
the unit has detected metal and a Reset Button.
See Figure 1.
Type: JIC NEMA 4
Size: 16" x 14" x 6" (406 x 356 x 152 mm)
Weight: 33 Lbs (15 kg) (Includes All Electronics)
ELECTRONIC/LNTERFACE MODULES
All the electronics and controls for the Detector
are contained in two modules, the Interface Module
and the Electronic Module shown in Figure 2. The
Electronic Module houses the electronic circuitry
and components associated with metal signal
processing and analysis. Visible on the front panel
of the Electronic Module are the metal sensitivity
control knob, clip override control knob and L.E.D.
status indicators used to monitor the status of the
Detector’s self-test circuits. By removing the front
panel of the module, all of the electronics are ex-
posed for calibration and troubleshooting. All con-
nections for the Electronic Module are made through
a 36-pin connector located along the bottom edge
of the module. When the modules are in place, this
connector mates with a connector on the Interface
Module.
Part I - Operation & Description

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The Interface Module interconnectors all external
signals and power to the Electronic Module. This
module houses the power transformer, solid state
relays and interface circuit board. Visible on the face
of the Interface Module are system fuses and two
terminal blocks for external wiring; all are clearly
identified. The right terminal block, a 14-pin, 3/8"
center screw type, connects the Detector’s external
transducers and signals. The left terminal block, a
6-pin, 7/16" center screw type, is used for all con-
nections handling the A.C. Iine voltage.
ELECTRONIC INTERFACE
MODULE MODULE
Size: 10.5" x 8" x 1.5" Size: 11" x 4.5" x 4"
(267 x 203 x 38 mm) (279 x 114 x 102 mm)
Weight: 2.5 Lbs (1.1 kg) Weight: 4.75 Lbs (2.2 kg)
SEARCH COIL ASSEMBLY
The Search Coil Assembly includes receiver and
transmitter antennas, mounting frame and inter-
connecting cables. Each assembly is custom de-
signed to suit its particular application. Please refer
to the Frame Assembly Diagram.
RECEIVER COIL
The receiver coil is typically located under the con-
veyed material within 1" (25 mm) of the conveyor
belt. An aluminum enclosure shields the recover
coiI from electromagnetic interference. Mounting
tabs are located on the aluminum shield to attach
it to the material handling structure.
TRANSMITTER COIL
The transmitter coil is located opposite and parallel
to the receiver coil. The distance between the trans-
mitter and receiver (aperture) is typically 2" - 4" (51-
162 mm) greater than the maximum burden depth
of the processed material. Strong, yet lightweight,
molded fiberglass is used for applications that do
not have vibrating or moving metal objects nearby.
A shielded version may be recommended if addi-
tional protection from electromagnetic interference
is required.
MOUNTING FRAME
Two types of mounting frames support the anten-
nas on troughed and slider bed conveyors. Special
designs are available to accommodate other types
of material handling systems. The swing-away as-
sembly shown in Figure 3, is used with non-shielded
transmitter coils or when the transmitter must be
protected from oversized conveyed materials. The
fixed assembly, shown in Figure 4, is used for high
sensitivity applications or when a shielded trans-
mitter is required.
INTERCONNECTING CABLES
Shielded cables connect the receiver and transmit-
ter to the Main Control Enclosure. The cables are
cut to a specified length at the Factory. Any alter-
ation to the cables may degrade the Detector’s
performance. Consult the Factory if other cable
lengths are required.
CLIP DETECTOR (IF APPLICABLE)
The clip detector consists of a compact sensor head
and mounting bracket. The clip detector senses the
proximity of repair clips as they pass over the sen-
sor’s head. Once the clips are detected, the Metal
Detector is desensitized or disabled for a period
which has been preset at the factory.
Part I - Operation & Description (cont.)

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Part I - Operation & Description (cont.)
FIGURE 1. MAIN CONTROL ENCLOSURE (NEMA 4, 4X, 7 OR 9)

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Part I - Operation & Description (cont.)
FIGURE 2. ELECTRONIC MODULE

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PLEASE READ THROUGH COMPLETELY
BEFORE BEGINNING WORK!
A. UNPACKING
Upon receipt of the crate(s) containing the Metal
Detector System, inspect the contents for physical
damage and missing parts. If anything is broken or
missing, please contact the carrier and notify the
supplier immediately.
B. SITE SELECTION &
PREPARATION
While each application is unique, the guidelines
listed below apply to most installations. Specific in-
formation concerning your installation can be found
in the Frame Assembly and Control Connection
Diagrams. Follow the steps listed below to choose
the best location for the detector.
• Choosealocationforthedetectorsothemater
ial handling system has ample time to react to
tramp metal. Locate the detector far enough in
advance of the head pulley so the belt can come
to a stop before the metal falls off the end of the
belt If a diverter is used, consider the reaction
time of the system and speed of the conveyor
belt.
• Selectasitewithminimumvibration.Highvibra
tion areas may degrade detector sensitivity and
shorten component life.
• Locate the Search CoilAssembly away from
sources of airborne electrical interference emit-
ted from variable-speed drives, large motors,
ballasts, FM radios, induction furnaces and oth-
er radio frequency (RF) sources. Although the
receiver coil is shielded on five sides to reduce
the effects of RF noise, the surface facing the
transmitter is unshielded and therefore suscep-
tible to RF noise. Because RF energy travels
along a straight line (line-of-sight), position the
receiver coil or relocate RF sources so they are
below or out of the direct line-of-sight with the top
of the receiver. Cables carrying high voltage or
varying loads must be enclosed in steel conduit,
grounded at both ends and located at least 4'
(1.2 m) from the detector antennas.
• Positiontheentiresearchcoilassemblysothat
the bottom coil (usually the receiver) is equally
spaced between the two adjacent idler rollers.
Center the receiver coil. Do not center the 2" x
2" uprights.
• The magnetic eld generated by the transmitter
coil induces eddy currents in nearby metal cross
bracing, stairways, handrails and pipes. These
eddy currents may cause false tripping if the current
path intermittently makes contact. Eddy current
loops can be broken by cutting the conductive
paths in these structures. Use non-metallic hard-
ware as required to restore structural support. If
conveyor idlers are used in your application, the
idlers adjacent to the Search Coil Assembly may
require modification or isolation to break eddy cur-
rent loops. Refer to the Conveyor Idler Modification
Diagram (if applicable) for details.
• If the Search CoilAssembly is located where
a metal skirt passes through the coils, it must
be replaced with a five-foot (1.5 m) section of
non-metallic material (i.e., wood or plastic).
• Relocate or tightly secure moving or vibrating
pieces of metal such as cables, conduit and
piping within 36" (914 mm) of the Search Coil As-
sembly. Remove metallic decking, skirt boards,
cross bracing and return idlers below and within
3' (914 mm) of the center line of the receiver coil
(upstream and downstream).
C. MOUNTING - SEARCH COIL
ASSEMBLY
Note the material flow direction arrows match marks
and other identification on the Detector components
before beginning work. Please refer to the Frame
Assembly Diagram for installation
• Fastenthereceivercoiltothematerialhandling
system. Shim the unit as necessary to provide a
uniform and sturdy mounting surface. Maintain
clearance between the coil and any moving ob-
jects. Do not torque, twist or use excessive force
when fastening the coil to the structure. Do not
drill or weld the coil
Part II - Installation

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• Securetheframeassemblytothereceivercoil.
Make sure the assembly is aligned. Use the
hardware provided as called out in the Frame
Assembly Diagram. If aluminum side shields
are used to reduce RF noise, use the electrical
isolation bushings and spacers (provided). The
Detector will not operate properly if the aluminum
side shields make electrical contact with either
the receiver or transmitter shield, or contact with
metal conveyor components.
• Fastenthetransmittercoiltotheframeassembly.
If a swing-away assembly is used, make sure
the transmitter brackets rest squarely with the
uprights and move freely. Be careful to install the
bolts, washers and nuts in the proper sequence
to allow free but controlled movement of the
brackets.
• Inspectthecoilsandframeassemblyforalign
ment and fit. Tighten all connections. The entire
assembly should be rigid and sturdy.
D. MOUNTING - MAIN CONTROL
ENCLOSURE
After installing the Search Coil Assembly, select a
place to mount the Main Control Enclosure for ease
of operation. Avoid high vibration areas. Note the
length of interconnecting cables and the location of
the connectors on the receiver and transmitter coils.
• TheEnclosureshouldbepositionedsothefront
panel hinge is on the left side
• Fabricateandinstallasun/rainshadeforadded
protection over the Enclosure if it is mounted out
doors. Do not obstruct the natural airflow around
the Enclosure.
• Familiarizeyourselfwiththetypeofelectricalcon-
nections required for this installation and any safety
precautions before proceeding. Please refer to the
Control Connection Diagram for information about
connections and color code hook-up.
• Useanelectrician’sconduitpunchordrilltomake
either 1/2" or 3/4" conduit entries on the bottom of
the Enclosure. The Control Connection Diagram
shows where to position each entry
Remember to remove all metal shavings when you
are finished. Use caution to not damage the elec-
tronics and to ensure that no metal particles enter
the electronics. Do not run metal conduit along the
sides or near the Search Coil Assembly.
• Paycloseattentiontothetypeofelectricalwires
routed in each conduit and the location of each
connection on the Interface Module. The receiver
and transmitter cables must be routed in sep-
arate conduit 6" apart from the search coils to
the control box. Do not run power wiring near
the transmitter and receiver cables. Do not run
power wiring connected to TB2 with low voltage,
signal wiring from TB1 in the same conduit.
• All line voltage connections terminate at TB2.
Install line voltage cables between devices
con- trolled by the Detector including diverters,
auxiliary relays, marking devices, alarm horns
or motor control equipment and TB2 in the Main
Control Enclosure. The direct or timed outputs
should not be connected to a Programmable
Logic Controller (PLC) or other low voltage
computer interface equipment that may
require dry contact closures. The direct and
timed output contacts are typically programmed
as normally “OFF” at the Factory. They may be
set to normally “ON” if required. Refer to the
System Programming Section for details.
• Connecta115/220VAC(50/60Hz),singlephase
power line with at least 10 amp capacity to TB2.
Make sure to connect an electrical ground to
terminal #3. The power should be the “cleanest”
available and free of significant voltage variations
or spikes. Do not connect the Detector to a line
which is used for operation of motors or motor
controls. Proceed with the Start-Up & Calibration
Section before applying power.
CAUTION:The Interface Module is preset at the
Factory for 115 or 220 volt (+10%), 50/60 Hz,
single phase operation. If the source is different,
contact the Factory for instructions to select the
proper voltage source.
Part II - Installation (cont.)

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E. SWING-AWAY SWITCH (IF
APPLICABLE)
The Swing-Away Cutout Switch (Optional) is a pre-
wired switch mounted on the swing-away, bracket.
Its purpose is to prevent the Metal Detector from
tripping when the transmitter coil is hit by an over-
burden of material. Route the free end of this cable
in the same conduit as the transmitter cable to the
Main Control Enclosure. Refer to the Control Con-
nection Diagram for hook-up.
F. CLIP DETECTOR (IF
APPLICABLE)
Install the Clip Detector Unit as follows:
• RefertoControlConnectionandFrameAssem
bly Diagrams.
Position the Clip Detector Sensor approximately
(but no closer than) 2' (610 mm) from the center
line of the receiver coil on the upstream side of the
Search Coil Assembly. If there are idlers adjacent
to the search coils, position the Clip Detector Sen-
sor approximately 1” to 3" (25-76 mm) upstream of
the nearest upstream idler before the Search Coil
Assembly. The flat face of the Clip Detector should
be facing toward the belt with approximately 1/2"
-1" (12-25 mm) of clearance. This clearance must
be maintained in order to assure proper operation.
The Clip Detector should be a few inches (about 50
mm) from the edge of the belt. Do not mount the
Sensor too far from the edge, as tramp metal Iying
close to the belt may trigger the sensor and pass
through the search coils as a repair splice.
• With the Clip Detector Sensor in the proper
position below the belt, weld the 3/4” support
pipe (provided) to the conveyor name. The pipe
may be cut to the proper size for an easier fit.
The multi-axis swivel joint will provide adequate
movement for proper adjustment.
• ItisrecommendedthattheClipDetectorcable,
running to the Main Control Enclosure be in-
stalled in conduit. The same conduit that houses
the transmitter coil cable may be used.
• Feed the Clip Detector cable into the conduit,
from the Clip Detector end to the Main Control
Enclosure.
• Cutoffexcesscable.Connectwirestoterminal
block (TB1) using the supplied spade lugs. Refer
to the Control Connection Diagram for color code
hook-up. Be certain all wires are attached secure-
ly and connected to their proper terminals.
• Wheremetalrepairclipsareusedtwoormore
clips close together must pass directly over the
Clip Detector Sensor in order to activate it. If a
small patch of clips is used on the belt which
would not pass directly over the Clip Detector,
reference clips are required. Reference clips
are made by installing two or more clips which
will pass directly over the Clip Detector to trip it
when a small patch passes by. Numerous repair
and reference clips on the belt will degrade the
Detector’s performance because it will frequently
be in a desensitized mode.
G. MARKING DEVICE (IF
APPLICABLE)
The Marking Device is a pressurized solenoid
activated liquid spray system which pinpoints the
location of tramp metal to eliminate costly search
and downtime.
SPECIFICATIONS
Tank Pressure Rating: 150 psig (maximum working
pressure) (10 bar)
Tank Capacity: 3 Gallons (11.1 l) (liquid)
Operational Voltage: 115/220 (50/60 Hz), 15 Watts
Air: Plant air or any source of 100 to 200 psig inert
gas (6.5-13 bar)
INSTALLATION INSTRUCTIONS
• RefertotheSensingCoilandFrameAssembly
Drawing, for layout of the Marking Device on
the belt.
• Positionthesolenoidsupportuprightandcrossarm
as shown. Distance from the coils should be 3’ to
6' (.9 m to 1.8 m). Clamp in place temporarily
Part II - Installation (cont.)