EXCELL PRECISION CO., LTD

FAQ

Please refer to the manual to install the product.

If you have any questions, please contact us. Our technicians will replay your questions.

There are too many E2 and less E1 for internal value (only for MTW, CAW models)

Internal value is too low
Internal value is too high

[Solutions]
1. Please calibrate the internal value.
First open the scale housing. On AD board , there are 2 VR: VR3 and VR 4. VR3 is used to calibrate weight and VR4 is used to calibrate internal value.
For example: MTW300kg
If E1 –08575 appears and it does not count down to zero after power on the scale, please adjust VR4 to -12450
2. after adjust VR4, the display still shows -08455, and the internal value can not arrived -12450. Please shorten the resistance value of R29. If the internal value is -19995, please amplify the resistance value of R29.

[Notes]
Whether to change the factor resistance or resistance value of R29, please calibrate the weight and internal value again.
How to see the internal value?
Please press zero key and then press conformation key after power on the scale.

What to do, if the display shows E3? (Only for MTW, CAW models)

1. Please press conformation key to enter into calibration mode, and do the calibration again.
2. When enter into the calibration mode, the display shows which means the multiplying power is not enough (This phenomenon appears when exchange the Load Cell or change the specifications)
For example
When exchanging the Load Cell or changing the specifications, the display shows and the weight can not be calibrated. Please modify the multiplying power. E.g. put the full scale weight on the platter and displays 24000COUNT which means the multiplying power is too small.
Please modify the resistance value of R11, R14, and R15 on AD board to change the count.
24000COUNT 21000-27000
30000COUNT 24000-30000
If COUNT is in above rang, the display does not show .
36000COUNT is adjusted by weight. (Please adjust VR3)

The linearity of load cell is good or bad?

Steps:
1.please adjusts the avometer to DCV200 m. Open the housing of the scale, cut off the PIN4 and PIN5 of CN2 on AD board.
2. Please connect PIN4 and PIN5 to avometer. Test the data when nothing on the scale and record④. Put weight (10 kg) on the scale and record the data①. Put the second weight (20kgin total) on the scale and record the data②. Put the third weight (30kgin total) on the scale and record the data③.
Record the tolerance:③-②，②-①，①-④
Check whether the three tolerance < range of nonlinearity tolerance of L/C.
Generally, the tolerance ≦ 0.0004mv/v
For example: To test PW6KR~L/C
0/3~output 0.254mv/5=0.0508mv
1/3~output 3.508mv/5=0.7016mv
2/3~output 6.7625mv/5=1.3525mv
3/3~output 10.0155mv/5=2.0031mv
1 ~ 2.0031mv-1.3525mv=0.6506mv
2 ~1.3525mv-0.7016mv=0.6509mv
3 ~0.7016mv-0.0508mv=0.6508mv
4 ~0.6509mv(max)-0.6506mv(min)=0.0003mv
5 ~0.0003mv < 0.0004mv ok
Note: The voltage is divided by 5 because the standard specification of L/C is mv/v.

What to do if the scale is unstable and it can not do external calibration?

For example:
Scale: dual range, capacity:120kg Power on the scale and put20kgon the platter, the display shows20.12kg. It is useless to adjust VR3 of SPAN. Please shorten the resistance value of R11, R14 or R15 and then adjust the VR. (if the weight is not enough, please enlarge the resistance value)

Whether to change the factor resistance or resistance value of R29, please calibrate the weight and internal value again.

The Zero point is unstable?

1. Scale must be used under a stable temperature and stable air flow.
2. If there is a windbreak, please use it.

Please note the following tips when using the scale

When you operate the scale following the manual, the following condition still appears. Please contact your supplier and do not purchase others components to exchange.
1. the storage battery is damaged
2. the charger is damaged
3. You can not turn on the scale or the keypad is damaged.
4. There is sth. Wrong with LCD
5. No backlight
6. the display shows error massage(except the error massage in the manual )
7. the battery indication appears (the power is enough)
8. zero point is unstable (except environment factors)
9. The scale can not weight full scale. (protection screw is not dismantled)
10. Wrong operation: Please refer to the manual If the scale is damaged, please contact your supplier or Excell precious company to ensure your rights and interests.

Some tips to maintain the scale

1. Clean the scale Dust cover:
use the wet cloth to clean the outer of the dust cover. Please do not let the water enter into the hole of the scale. No dust cover: please cover other dust cover. If there is no suitable dust cover, please clean the housing of the scale with little cleaning oil. Please do not clean the panel with cleaning oil.

2. Dust cover
if the dust cover is damaged, please change a new one.

3. charging
The scale should be charged every 3 months to prevent failure of the internal rechargeable battery.

How to judge impedance output or input of Load cell

Steps:
1. Please adjusts the avometer to2k
2. Open the housing of the scale, Cut off the PIN 1 and PIN 2 of CN2 on AD board
3. to test PIN1 and PIN2 with avometer and impedance should be about 420Ω.Cut off the PIN4 and PIN5 of CN2. to test PIN4 and PIN5 with avometer and impedance should be about 350Ω. If the result is 700Ω, please change the Load cell.

Note: How to connect the E+.E-.S+.S- of L/C to CN2 on AD board?
different connecting ways for different L/C
‧ 世銓~(Red cable E+)( black cable, blue cable E-)( green cable S+)(white cable S-)
‧ NMB~( Red cable E+)( white cable E-)(green cable S+)( blue cable S-)
‧ HBM~( green cable E+)( black cable E-)( Red cable S+)( white cable S-)
‧ TEDEA~( blue cable E+)( black cable E-)( white cable S+)( Red cable S-)
※S+ and S- of CN2 connect the input impedance
※E+ and E- of CN2 connect the output impedance

How to test output voltage (mV) of L/C

Cut off the PIN5 and PIN4 on AD board. Please adjust the avometer to DCV200 mand test PIN4 and PIN5 with avometer after power on the scale. The voltage should be in +2mV~-2mV. If the voltage is beyond the range, please change the load cell.

When the voltage is beyond above voltage, the display shows OF, at this time please test the volt of PIN 10 of U1 7135. If it is within -2V~ 2.5V, please enlarge resistance value of R29.

Example: if the display shows OF after power on the scale. Do not connect the load cell. Power on the scale again and test the volt of PIN 10 of U1 7135. The volt is -2.2V, resistance value of R29 is 4.53K. Please enlarge the resistance value as 20K, test the volt of PIN 10 of U1 7135 as -1.53V and then adjust VR.

Note: the resistance value of R29 should less then 50K. If the display still shows OF after change the resistance value of R29, please change the Load cell

Is the Insulation resistance in good condition?

Please adjust the avometer to DCV 20 m. cut off the 4 cable on L/C. please touch one stick of avometer to the platter and touch another stick to one of the 4 cable. The avometer displays 1(normal). If displays other number, the Insulation resistance is too small. Please change the Load cell. (All the 4 cable should be tested)

How to do L/C compensation?

When the zero voltage of L/C is less then 2mv/5v, it can do L/C compensation. Please adjust output of S+ and S- to the balance condition.

Example: the output volt of L/C: S+2.50mv S- 2.42mv The tolerance of S+ and S- is 0.68mv. At this time S- 2.42mv need do L/C compensation這compensation way is as following: connecting changeable resistance to E+ and S- E+5v E-G S+2.50mv S- 2.42mv when it adjust S- to 2.50mv and S+ to 2.50mv, and test changeable resistance and record. Then record fixed resistance value of E+ S-. E+5v E-G S+2.50mv S-2.50mv