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7.01
Apply Power to the System
Assuming that all the entered Parameters are correct and all the equipment is installed properly,
the scale must now be calibrated. Without calibration, the scale will only approximate the RATE.
First, however, on scales with LVDT(s) (
L
inear
V
oltage
D
ifferential
T
ransformer), a procedure
needs to be performed to verify that the LVDTs are in alignment. Use one of the following two
sections, depending upon whether the scale has a SC200 or SC400 signal conditioner, to verify
(and re-align if necessary) the LVDT alignment.
Now turn on the conveyor, power up the WP20, make sure the belt is clean, and let the entire
system run for at least half an hour (longer in colder environments) so it attains temperature
stability. If the WP20 displays a "Scale Data Error", there’s a communications problem between
the scale (the signal conditioner) and the WP20. This problem must be corrected before
continuing. Consult Section 9.08, “scale data error”, for troubleshooting tips.
7.02 LVDT Alignment for Scales with a SC400 Signal Conditioner
(WY10, WY10HD, WY20 scales Only)
The WY10 and WY10HD have two LVDTs, while the WY20 has four LVDTs. Alignment of the
LVDTs is critical for scale accuracy. The LVDTs were aligned at the factory, but it must be
verified that they are still in alignment after shipping and installation. Turn the belt off, leave the
MS20 on and remove both side covers from the scale. On the SC400 PCB, DIP switches SW3
and SW4 are used in the alignment procedure (see the figure below). First verify that SW3 and
SW4 are set to the positions shown on the first or second lines in the following chart depending
on the particular scale at hand. Next, to verify proper alignment, connect a DC voltmeter across
the test points (again see the figure). If the voltage is 2.50 +/- 0.02 VDC, the LVDTs are
sufficiently aligned and move on to the next section, however, if the voltage is outside the stated
range, continue as follows.
CHAPTER 7 – CALIBRATION
Содержание Tecweigh 20
Страница 2: ... 1 ...
Страница 10: ... 9 2 09 I O Quick Reference Guide ...
Страница 20: ... 19 ...
Страница 24: ... 23 4 03 WY15 and WY25 Scale Wiring load cells ...
Страница 25: ... 24 4 04 HY15 and HY25 Field Wiring ...
Страница 26: ... 25 4 05 WY10 WY10HD and WY20 Scale Wiring LVDTs ...
Страница 27: ... 26 4 06 Chart Recorder Data Logger using the 4 20 ma output ...
Страница 28: ... 27 4 07 Chart Recorder Data Logger using the HFR output ...
Страница 29: ... 28 4 08 Remote Rate Total Display 4 09 Remote Tons Counter ...
Страница 30: ... 29 4 10 Radio Transceivers Local Scale Remote Processor ...
Страница 31: ... 30 4 11 Radio Transceivers Local Processor Remote PLC PC or Remote Display ...
Страница 32: ... 31 4 12 Radio Transceivers Local DC Generator Remote Processor ...
Страница 33: ... 32 4 13 Radio Transceivers Local DC Generator and Processor ...
Страница 34: ... 33 4 14 Multiple Processors to Tecweigh Multi Scale Display MSD ...
Страница 35: ... 34 4 15 Interposing Relay External 120 vac Power 4 16 Interposing Relay Internal 30 vdc Power ...
Страница 61: ... 60 SC300 PCB WY15 and WY25 SC400 PCB WY10 and WY20 ...
Страница 71: ... 70 10 01 WY10 Dimensions CHAPTER 10 DIMENSIONS ...
Страница 72: ... 71 10 02 WY10 HD Heavy Duty Dimensions ...
Страница 73: ... 72 10 03 WY15 Dimensions ...
Страница 74: ... 73 10 04 WY20 Dimensions ...
Страница 75: ... 74 10 05 WY25 Dimensions ...
Страница 76: ... 75 10 06 HY15 and 25 Dimensions ...