NUT-WELD 3796944 - Caterpillar

Image1.4.1
To measure the DC bus capacitor voltage:
1. Observe the lock-out/tag-out procedures.
2. Wait fifteen minutes for the DC bus capacitors to discharge.
3. Remove the front cover of the VFD to access the PA/+ and PC/- terminals.
IMAGE 1.5.1 shows the VFD front with the front cover and with the front cover removed.
4. Set the voltmeter to the 1000 Vdc scale. Measure the voltage between the PA/+ and PC/- terminals.
5. Verify that the DC bus voltage has discharged below 42 V before servicing the VFD. If the DC bus capacitors will not discharge below 42V, contact your local Schneider Electric representative. Do not operate the drive.
6. After verifying the DC bus voltage is below 42V, reinstall the front access cover.
Image1.5.1
STEP 4: Terminal Block Replacement:
The following seven terminal blocks (IMAGE 1.6.1) will need to be replaced, F521, F522, F523, E857A, E858A, PR1, and PR2 (IMAGE 1.6.2).
Image1.6.1
Image1.6.2
4A. Loosen the securement screw of the top DIN rail end-anchor block with a flat head screw driver and remove it or slide it vertically upwards as far as possible.
4B. Slide the terminal blocks F521 - PR2 upwards about a 1/4 to 1/2 inch (6 - 13 mm). Replace each terminal block one at a time to minimize miss-wiring. The conductor wire identification is printed onto the conductor's insulation. Refer to IMAGE 1.8.1 and IMAGE 1.8.2 for conductor wire identification and terminal wiring diagram.
Image1.8.1
Image1.8.2
4C. Start with the PR2 terminal block first (seventh one from the top, refer to IMAGE 1.9.1).
Remove the wiring from the terminal block. Terminal blocks have spring cage clamp type terminals. Refer to IMAGE 1.9.2 for illustration on how to remove the wiring from the terminal block using a small flat headed screw driver.
Insert screw driver into respective terminal clamp lever opening. To open terminal clamp, push down on the screw driver and pull the screw driver in the opposite direction of wire terminal. This will cause the tip of the screw driver to open the spring clamp mechanism allowing the conductor to be removed from the terminal block. Repeat this process for all the terminals of this 3 pole terminal block. Then remove the terminal block from the DIN rail.
Image1.9.1
Image1.9.2
4D. Replacement screw-type terminal blocks will have the same terminal marker identification as the old terminal blocks. Select the replacement terminal block with the same designation as the one just removed and install it onto the DIN rail. Keep the same orientation as previously removed terminal block, single terminal on the left side and double terminal on the right side, refer to IMAGE 1.10.1. Insert the previously removed wiring into the new terminal block and tighten terminal screws to 0.8 N-m (7 in-lbs).
Image1.10.1
4E. Slide terminal block downward firmly against the one below it. Repeat steps 4C ? 4E for each of the remaining terminal blocks needing to be replaced.
4F. Once all seven (7) terminal blocks have been replaced. Recheck the wiring to each terminal block against IMAGE 1.12.1 and IMAGE 1.12.2. Reinstall the top DIN-rail end anchor block and tighten its securement screw.
Image1.12.1
Image1.12.2
4G. IMAGE