Eriez 1250 ANALOG, Installation, Operation And Maintenance Instructions

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For calibration of the clip gain follow the steps
below:
• Run the belt at normal running speed and maxi­
mum belt load.
• Verify that the clip timer, status indicator No. 7
lights each time a clip passes the sensor head.
If it does not, adjust the clip sensor head as
described in Section II.F.
• Adjust the Clip Override control knob, shown in
Figure 2, to a setting of 5.
• Remove the cover as described in Section IV.A
without changing the setting on the Clip Override
control.
• Adjust the Clip Gain, Switch S5 shown in Figure
5, to the highest gain that does not trip the De-
tector when the clips pass. If the unit continues
tripping even at the minimum clip gain of 1, the
desensitized length of the belt may be too short.
In other words the system is switched back to full
sensitivity before the clips are completely out of
the Detector’s field. To correct, increase the clip
detector time delay as described in Section IV.D.
• If all other functions are properly programmed,
replace the cover as described in Section IV.A.
Return the controls to recorded settings.
• Calibrate the Clip Override as described in Sec-
tion III.C.
D. CLIp DETECTOR TIME DELAy
If the clip detector is used, the length of belt desen-
sitized or disabled to permit the clips to pass can be
adjusted by properly programming the clip detector
time delay switches S1-4, 5, 6 & 7. The locations of
these switches are shown in Figure 5. The range of
delay times is from .1 seconds to 4.8 seconds as
tabulated in Table 1. These switches are set at the
factory according to customer requirements and
should not be adjusted unless absolutely necessary.
As long as the Detector is desensitized or disabled,
the clip timer, status indi cator No. 7, will remain lit.
part Iv - System programming
(cont.)
E. DELAy BEfORE ALARM
The timed output alarm can be accurately pro-
grammed with a time delay before turn on. This
allows the conveyed material to travel for a pro-
grammed period before the timed output alarm
signal is energized. Typically this feature is used in
conjunction with a marking device or diverter gate
to delay the system until the detected tramp metal
has reached the auxiliary equipment. Switches
S2-1 through S2-5 control this time delay from .01
to 17.0 seconds. Refer to Table 2 for tabulation of
the delay time versus switch set tings and Figure 5
for the switch locations.
f. TIME ALARM ON
The timed output can be accurately programmed
to remain energized for a timed period once it is
switched on. This feature can activate a diverter
gate, sound an alarm for a given period, command
a marking device to spray a given length of the belt,
etc. Switches S3-1 through S3-5 control this time
delay from .01 to 17.0 seconds. Refer to Table 2 for
a tabulation of the delay time versus switch settings
and Figure 5 for the switch locations.
TABLE 1. CLIP TIME DELAY
(SWITCH S1)