AV56A 3
VERIFY ROTOR LOCATION
To ensure the rotor is properly located on the shaft: remove the back
cover if factory-preinstalled, and verify that the outer face of the rotor
is at the same depth as the alignment grooves, using a straight edge
tool. (Figure 3)
CAUTION
Do not use silicone sealants or caulk of any kind on the
motor or encoder face; these can cause misalignment
or sensor scraping damage. The AV56A electronics are
fully sealed; water may enter and leave the rotor area
as needed. A drain hole option is available if frequent
moisture buildup is expected.
COVER INSTALLATION
Covers must not interfere with the motor shaft or rotor. The longest
shaft that can be used without interfering is 0.69” [17.5mm] with a
standard flat cover (Cover Style option “F”) 0.96” [24.3mm] with Dome
Cover Option “D” and 2.5” [63.5mm] with an extended “pie pan” cover
(Cover Style option “E”). Through shaft covers with seals are avail able
for other applications (Cover Style option “T”).
EXTENDED COVER MOUNT
(Cover Style option “E”)
The extended cover mounts to the encoder housing using quantity 4
#6-32 x 0.31" screws, lock washers, and thread locker.
THRU SHAFT AND FLAT COVER INSTALLATION
(Cover Style option “T” and “F”)
The housing has a machined step in the outboard face to accept the
cover and a recessed groove for the retaining ring. Insert the cover,
line up ears on cover, smooth side facing out, fully into the machined
step until it seats against shoulder. Using a spiral assembly method,
install the retaining ring by first inserting the squared off end into the
machined groove. Flex the ring and insert it into the groove walking
it around the perimeter (A flat blade screwdriver can be used). Final
position should have the ring fully seated into groove. Remove the
cover by reversing above procedure, starting with the tang end.
V-RING INSTALLATION FOR THRU SHAFT COVERS
(Cover Style option “T”)
For thru shaft covers, verify that the shaft passes completely through
the hole in the cover. Apply a small amount of silicone lubricant to
the cover plate around the thru shaft hole. The V-Ring seal should
compress axially when it is pressed against the clean, smooth face
of the cover plate. See Figure 4 for proper installation and V-Ring
compression.
WIRING
Caution
Be sure to remove power before wiring the encoder.
Be sure to ground the cable shield: It can be connected
to case ground at the encoder, or grounded as the
receiving device, but should not be grounded on both
ends. See note below for Danaher/Northstar wiring.
Refer to the wiring diagrams for specific information on each option.
The AV56A can be wired for single phase or two phase, either with
or without complements, with or without markers. For bidirectional
operation, Phase A channel leads phase B channel for clockwise shaft
rotation as viewed from the anti-drive or accessory end of the motor
(AV56A mounting end).
NOTE
Wiring option “G” provides a pinout compatible with
NorthstarTM encoders, with a cable shield connection on
pin 10. Note that this option does not ground the shield;
Avtron still recommends grounding the shield at the
drive end of the cable for all wiring options.
CORRECTIVE ACTION FOR PHASE REVERSAL
1) Remove Power.
2) Exchange wires on cable, either at encoder cable end,
or at speed controller end (but not both).
a) Single Ended 2 Phase Wiring (see wiring diagram)
Exchange A and B at the use end of the wires.
b) Differential 2 Phase Wiring (see wiring diagram)
Exchange either A with A in the phase A pair OR
B
with
B in the phase B pair but NOT both.
3) Apply Power.
4) Verify encoder feedback is correct, using hand rotation
of shaft, or jog mode of the speed controller.
Interconnecting cables specified in the wire selection chart are based
on typical applications. Physical properties of cable such as abrasion,
temperature, tensile strength, solvents, etc., are dictated by the specific
application. General electrical requirements are: strand ed copper,
22 through 16 AWG (Industrial EPIC connector type options can use
14 AWG), each wire pair individually shield ed with braid or foil with
drain wire, .05 uf of maximum total mutual or direct capacitance,
outer sheath insulator. See specifications for maximum cable length.
Strand ed 22 AWG wire should not be used for cable runs great er then
61 meters. If 22 AWG is used with EPIC type connector options the wire
ends should be tinned.
FAULT-CHECK
After power-up and the rotor position is checked by the sensor, the
Fault-Check LED will turn GREEN.
If the adaptive electronics reach their adjustment limit for any reason,
the Fault-Check alarm and LED will notify the drive and operator of an
impending failure. The LED will turn RED if the Adaptive Electronics
reach their adjustment limit. This output occurs before an actual
failure, allowing steps to be taken to replace the unit before it causes
unscheduled downtime. Fault-Check annunciation is available as an
“alarm” output through the connector and as an integral LED.
TROUBLESHOOTING
If the drive indicates a loss of encoder/tach fault and the AV56A fault-
check LED is not illuminated, check the encoder power supply. If power
is present, check polarity; one indicator of reversed power supply is
that all outputs will be high at the same time. If the drive indicates
encoder fault, but the LED shows GREEN, then check the wiring
between the drive and the encoder. If the wiring appears correct and
in good shape, test the wiring by replacing the AV56A. If the new unit
shows GREEN, and the drive still shows encoder loss/tach fault, then
the wiring is faulty and should be repaired or replaced.
If the alarm output and/or LED indicate a fault (RED):
1. Remove the rear cover, and use the built-in gauge to check the
location of the rotor (see Figure 1). Ensure the label marked “This side
out” and/or cam screws is/are facing away from the motor.
2. Remove the AV56A from the motor. Clean the housing mounting
surface for the AV56A housing. Ensure the AV56A is directly mounted
on the motor, with no sealant, gasketing, or other materials, and is
firmly bolted in place.
If the alarm output and/or LED indicate a fault (RED)
On a properly mounted AV56A and the rotor is properly located, replace
the AV56A.
An oscilloscope can also be used to verify proper output of the encoder
at the encoder connector itself and at the drive/controller cabinet.
If the outputs show large variations in the signals at steady speed
(jitter or “accordion effect”, see figure 5), check rotor position. If the
rotor position is correct, the motor or shaft may be highly magnetized.
Replace any magnetized material nearby with non-magnetic material
(aluminum, stainless) (especially shafts). For GE CD frame motors and
similar styles, Avtron offers non-magnetic stub shafts. If variations
persist, consider replacing the encoder with super-shielded models,
option -005, or use retrofit shielding kits AVSKxxx yy z, where
xxx=model (ex: 56A), yy=rotor (ex: CB), and z=cover (ex: F).
