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Acu-Rite Companies Inc.

ENC 250

™  

MULTI-SECTION

10

• Coat the plastic plug with silicone grease and install it

into the tensioning hole.

• This completes the installation of the ENC 250.

Apply silicone grease to plug

and reinsert it

• With the readout properly mounted, route the cable with

sufficient slack loops for machine movement to the readout.

• Secure cables by fastening with clips or ties.
• Attach the encoder connectors to the readout.

Electrical shielding ...

• Connect a ground wire from the terminal on the back of

the readout to the machine or earth ground.

• Attach a ground wire from the machine to a solid earth

ground.

• With  the encoder attached to the cable connected to the

readout, check shielding by measuring resistance
between connector housing and scale unit.
Desired value: 1 ohm max.

If you experience difficulties with your installation, do the
following to determine the problem.

Checking the Readout

Difficulties on more than one axis are usually associated
with the readout.  Follow these steps to determine if your
difficulties are associated with the readout:
• Ensure that the linear encoder connectors are correctly

seated.

• Swap linear encoder cables at the readout  to see if the

problem is still shown in the same display.

• If the problem remains in the same display, the readout

may be in error. To determine if that is the problem,
repeat above steps with both encoders, but with only one
encoder connected at a time. This should allow you to
determine if the problem is with the readout or the
encoder.

• If the problem follows the connection change, the linear

encoder may be in error.

If the Readout is at fault, refer to “What to do” to arrange
for the parts necessary to repair your system.  If a linear
encoder appears to be at fault, proceed with “Checking the
Linear Encoders
”.

Checking the Linear Encoders

Problems on a single axis are usually associated with the
linear encoder or its installation.  Difficulties can be caused
by improper installation, loose or misaligned bracketry, or
a damaged or inoperable encoder.

Follow these steps to determine the cause of your system
difficulties:

• Confirm that your bracketry and installation does not

interfere with other machine structures through the
entire length of the linear encoder travel.

• Check for loose fasteners.  If you find loose fasteners, first

confirm that the linear encoder is installed to the
tolerances specified and then retighten the fasteners as
required.

• Confirm that the linear encoder is installed to the

specified alignment tolerances.  If the installation does
not meet the tolerances, reinstall the encoder according to
the “Installation Procedure”.

• Do not attempt to repair the reading head or scale

assembly.  The ENC 250 is field serviceable by assembly
replacement only.  Attempts to repair the encoder can
permanently damage it and void the warranty.

What to do

If an ACU-RITE linear encoder or readout is found to be at
fault, please contact your Authorized Distributor for
instructions prior to removing the encoders or readout.

Trouble Shooting

Summary of Contents for ENC 250

Page 1: ...REFERENCE MANUAL ENC 250TM MULTI SECTION Acu Rite Companies Inc SALES SERVICE A Tech Authority Inc 13745 Stockton Ave Chino CA 91710 909 614 4522 sales atechauthority com ...

Page 2: ...cables up to a maximum of 75 ft 22 9m for a VRO 35 ft 10 7m for a DRO Mounting hardware Brackets and accessories Contact your Authorized Distributor for a complete list of other products and accessories For future ordering information or warranty service record the linear encoder catalog number located on the scale assembly tag and the serial number from the reading head tag Catalog No Serial No A...

Page 3: ...t tip Screw Driver Torque Wrench Please follow these preparation guide lines Understand your mounting requirements Mount with lip seals down and away from the work area Brackets should be kept as short as possible and rigid Surfaces must be in good condition clean and free of dirt Remove paint from machined mounting surfaces Locate the machine s center of travel on the axis that the encoder will b...

Page 4: ...tical mounting Positioning 5 0 127mm 1 0 25mm End of scale clearance requirements Minimum clearance is required above the scale case top A minimum clearance of 5 0 127mm is required at each end of the scale case Use this information to plan your Linear Encoder installation Mount the linear encoders close to machine guide ways to ensure system accuracy Space between reading head casting and mountin...

Page 5: ...in the left end section as shown Pins should protrude approximately 5 8 15 87mm The seams on the roll pins face towards the inside of the scale case Repeat this step for all middle scale sections inserting the roll pins into the right end of each Insert roll pin with open slot facing in as shown Roll Pin Enlarged end view Left end section Apply RTV Silicone Rubber to the two sealant grooves in the...

Page 6: ...as done previously seating it against the 2mm spacer Attach the right end to the machine but do not tighten Clean off any excessive RTV sealant Center section installation 2mm Spacer 2mm Spacer Center scale section Roll pins installed Scale clip Transfer punch furthest mounting hole 1 4 20 x 1 2 M6 x12mm SHCS and washer 1 4 20 x 1 1 4 M6 x 30mm SHCS and washer Apply RTV to the two sealant grooves ...

Page 7: ...he axis travel first locate the high point This is the TIR point furthest away from the mounting surface along the axis travel Run an indicator along the front face to locate the high point Mark the location and set the indicator to 0 000 0 0mm Loosen the next two fasteners to the right of the high point Move indicator to the first hole location insert two M3 x 25mm SHSS leveling set screws Use th...

Page 8: ...the scale cavity Scale Tape Installation Scale Tensioner End view of tee slot Scale Tape Anchor block Retainer clip End view of tee slot Tape tension value 0 XXX mm Apply a small amount of silicone grease as a sealant to the two M3 x 8mm FHSS Insert the screws through the scale case and thread into the anchor block Tighten fasteners completely Draw a line onto the front of the scale case at a dist...

Page 9: ...ight pin Approximately 1 8 3mm over hang M3 x 12 CHMS Cover plate T 10 Torx screw 2 Plug Determine the cable exit direction before installing the reading head To change the cable exit direction remove the cover plate and rotate the cable 180 Changing cable exit direction Armor cable hex crimp Numbers on reading head casting Slide the reading head onto the scale case to the center of travel mark on...

Page 10: ...nstallation Remove the Reading Head shipping tool from the end of the scale case Attach the left end cap with M3 x 12 CHM screws provided in the hardware kit Tighten these screws securely to compress the end cap gasket M3 x 12 CHMS Move the axis so that the reading head is at the tape tensioning position indicated by the tension label on the right side of the scale Set the readout s display and en...

Page 11: ...ected at a time This should allow you to determine if the problem is with the readout or the encoder If the problem follows the connection change the linear encoder may be in error If the Readout is at fault refer to What to do to arrange for the parts necessary to repair your system If a linear encoder appears to be at fault proceed with Checking the Linear Encoders Checking the Linear Encoders P...

Page 12: ... output current 20mA VOL Low level output voltage 0 5Vdc Connecting cable Length 61m 2 ft Armor Connector DE 9P Mechanical Specifications Digital Resolution 5µm 0 0002 in Grating pitch 100µm 0 00393 in Scale medium Reflective Metal Tape Accuracy 20 C 15µm M 0 00018 in ft Max cable length 22 9m 75 ft VRO 10 7m 35 ft DRO Measuring length 6240mm 246 19 640mm 773 Force required to move reading head 3 ...

Page 13: ...le for incidental or consequential damages nor shall Acu Rite Companies Inc s liability for claims or damage arising out of or connected with this warranty or the manufacture sale delivery or use of the products with which this warranty is concerned exceed the purchase price of said products Digital Differential Acu Rite Companies Inc Acu Rite Companies Inc Acu Rite Companies Inc Acu Rite Companie...

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