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General Information 1-7

MN1269

Functional Description

The “LD” Servo Control consists of (1) a power supply, (2) a velocity control amplifier and
(3) fault logic circuitry.  The functional concepts are detailed below.

Power Supply

The power supply of a PWM bridge normally acts as a low output impedance voltage
source.  However, if an analog signal representing motor current is applied to the front
end of the amplifier together with a current command, the impedance of the PWM bridge
then becomes high.  These high impedance bridges exhibit a unique characteristic
referred to as current sourcing.  That is, motor current and therefore motor torque
becomes proportional to commanded input current.

Current Sense Coupler

The current sense coupler within the power amplifier serves as the current loop feedback
mechanism.  The unit isolates the high voltage motor signal from the low level control
circuitry.

Switching Configuration

The power amplifier contains a transistor bridge consisting of 2 limbs each containing 2
main switches.  These switches enable a limb output to be connected alternately from the
minus bus to the plus bus.  Both limb output signals or motor lines are normally zero with
respect to the minus bus.  However, if current is commanded as described above, the
average voltage on only one of the limbs will increase while the other limb remains
connected to the minus bus.  This switching configuration is referred to as the lower
circulation method.

Velocity Control Amplifier (VCA)

The high gain front–end velocity control amplifier accepts a speed command (Signal) and
a tachometer voltage (Tach) through the input connector.  The VCA clamped error signal
(C adjustment) is applied to the power amplifier as a current command.

Excess Current Limit

The long–term current clamp senses motor current and responds to overload conditions
beyond rated output.  If the comparator is tripped, it disables the drive, lights the Excess
Current (EC) indicator and pulls the interlock line “low” (if P4 is in latch position).

Surge Current Sensor

The surge current sensor pulls the interlock line low internally if the peak output current is
exceeded.  Once stopped, the drive must be cleared by connecting the reset line to
common momentarily (reset switch) or by interrupting logic power for 2 seconds.

Overheat Sensor

A thermal switch with significant hysteresis attached to the heatsink sets the EC (Excess
Current) latch if the heatsink temperature exceeds a preset level.  The latch operates the
EC fault indicator.  The fault condition is cleared after the heatsink temperature returns to
normal and a reset is given.

Left Limit, Right Limit

Limit switches are typically mounted on machinery to restrict the load from moving into
catastrophic over–travel conditions.  Limit switch polarity of the voltage on this line is the
same as that on the signal pin of the input connector.  The motor is wired such that
movement produces a positive voltage on NIML (Non–Inverting Motor Line) with respect
to IML (Inverting Motor Line).  Therefore, a positive input signal will cause the axis to
move in a rightward direction.  The limit switch leads are then wired confidently to the
appropriate pins of the input connector.

Decoupled Current Sense

The Decoupled Current Sense (DCS) pin is isolated from the high voltage motor lines.
Therefore, motor current is evaluated safely by connecting an oscilloscope or voltmeter to
the DCS pin of the input connector and common (TP1).

Tachometer Filter

The tachometer filter rejects tachometer commutator noise by reducing the tach path
bandwidth so that the high gain velocity control amplifier can be responsive yet reject
tach noise.

Servo Systems Co. • 115 Main Road • P.O. Box 97 • Montville, NJ, 07045-0097 

(973) 335-1007 • Toll Free: (800) 922-1103 • Fax: (973) 335-1661 

www.servosystems.com

Содержание LD Series

Страница 1: ...Servo Control Installation Operating Manual 7 98 MN1269 DC SERVO DRIVE Servo Systems Co 115 Main Road P O Box 97 Montville NJ 07045 0097 973 335 1007 Toll Free 800 922 1103 Fax 973 335 1661 www servo...

Страница 2: ...Tools 1 14 Section 2 Installation 2 1 Receiving Inspection 2 1 Location Considerations 2 1 Installing the Servo Control Card 2 1 Mount the Chassis 2 2 General Wiring Considerations 2 3 Power Wiring 2...

Страница 3: ...s 5 1 Current Torque Mode 5 1 Emergency Stop 5 2 Appendix A A 1 Condensed Installation Instructions A 1 Appendix B B 1 Jumper and Personality Module Settings B 1 Personality Module Current Settings B...

Страница 4: ...ith by unauthorized persons misused abused or improperly installed and has been used in accordance with the instructions and or ratings supplied This warranty is in lieu of any other warranty or guara...

Страница 5: ...t the start up procedure or troubleshoot this equipment WARNING Be sure all wiring complies with the National Electrical Code and all regional and local codes Improper wiring may result in unsafe cond...

Страница 6: ...diately above or beside heat generating equipment or directly below water or steam pipes Caution Avoid locating control in the vicinity of corrosive substances or vapors metal particles and dust Cauti...

Страница 7: ...roviding not only converted DC power to the motor but also precisely controlling current and velocity at the motor Its compact design requires very little enclosure space while its modular configurati...

Страница 8: ...us AC Other standard features include 20 kHz Inaudible Switching Test Points to aid during set up Jumper Settings allow easy tailoring for specific applications Personality Module for custom current s...

Страница 9: ...fy the LD Series Servo Control and Chassis The LD Series Servo Control cards can be configured with chassis to support up to four 4 axes at 160 VDC Figure 1 2 Identification Servo Systems Co 115 Main...

Страница 10: ...current and responds to overload conditions beyond rated output If the comparator is tripped it disables the drive lights the Excess Current EC indicator and pulls the interlock line low if P4 is in...

Страница 11: ...95 Shutdown Point Typical V 220 220 General LD2 LD4 Operating Temperature C 0 50 0 50 Weight lbs 14 20 6 Footprint inches Length 9 13 Width 10 5 10 5 Height 7 25 7 25 Notes 1 An isolation transformer...

Страница 12: ...0 50 Notes 1 RMS current limit is a built in function that turns off or folds back the servo control if the continuous current is exceeded for an extended period of time The EC fault indicator identi...

Страница 13: ...lso provided to verify the presence of 15 VDC PV 15 VDC MV AC for fans and logic AC and DC Bus voltage PB or BUS Bus Power Supply The bus power supply converts the 115 VAC input voltage into a DC volt...

Страница 14: ...the installer to vary the overshoot or stiffness of a motor as it is commanded to change speeds Response R R pot is used to adjust the overall velocity loop gain The effect of changing the gain enabl...

Страница 15: ...ule The personality module has 3 after factory adjustable settings for location see Figure 1 4 With the appropriate 1 resistor soldered into the socket peak current RMS current and the foldback level...

Страница 16: ...servo control Excess Current Overtemperature EC The purpose of the EC indicator is to identify either excess RMS current or over temperature condition Ground Fault GF The purpose of the GF indicator i...

Страница 17: ...medium large with 8 long shank required if replacing or adding servo control cards Add or remove modules Phillips screw driver medium Input connections to AC bus power Crescent Wrench 6 or 8 Disassem...

Страница 18: ...steam pipes CAUTION Avoid locating control in the vicinity of corrosive substances or vapors metal particles and dust Several other factors should be carefully evaluated when selecting a location for...

Страница 19: ...ted in General Precautions in section 1 3 Lay out the hole pattern according to the dimensions of your chassis Refer to Appendix A for dimensions 4 Cut any wiring openings needed in the cabinet debur...

Страница 20: ...ntly rated wire It is suggested that power wires be run as twisted pairs i e twist the wire carrying current with the same wire returning the current Twisting the wires will reduce radiated electrical...

Страница 21: ...tor and or terminal blocks Try to minimize the length of unshielded cable at these points Electrical Noise Suppression Electrical noise suppression requires a thorough system design using a combinatio...

Страница 22: ...ector see Figure 2 3 2 Connect the negative side tachometer lead wire of the first servomotor to the Tach input pin 6 on the 18 position Phoenix style input signal connector see Figure 2 3 Tie the tac...

Страница 23: ...itch has opened and disable its output in that direction unless the right and left limits pins 17 18 are tied to common Optional Wiring Single Voltage Input pin 4 to 2 The servo control can be configu...

Страница 24: ...d to the interlock line upon switch closure the output stages of all servo control cards will be disabled i e motors will coast to a stop with no holding torque See Section 5 for additional informatio...

Страница 25: ...2 8 Installation MN1269 Servo Systems Co 115 Main Road P O Box 97 Montville NJ 07045 0097 973 335 1007 Toll Free 800 922 1103 Fax 973 335 1661 www servosystems com...

Страница 26: ...y clockwise Low R Response Fully counterclockwise Low C Current Limit One turn clockwise Low B Balance Leave as shipped Center Note All pots have a 15 turn range and are without a hard stop You may he...

Страница 27: ...ssary to turn the T pot a few turns counterclockwise to achieve the desired speed 8 Slowly turn the C pot to the full clockwise position if the servo control s peak current is less than the rated peak...

Страница 28: ...ied personnel should attempt the start up procedure or troubleshoot this equipment WARNING Do not remove cover for at least five 5 minutes after AC power is disconnected to allow capacitors to dischar...

Страница 29: ...reset servo control VE Bus Voltage too high Check fuse on shunt regulator Recheck voltage and if problem still exists disconnect power to each servo control individually and isolate which servo contr...

Страница 30: ...hop dust in some environments tends to be electrically conductive and can cause servo control malfunction 1 If cleaning is needed carefully vacuum loose dirt or use dry compressed air 2 Remove power a...

Страница 31: ...4 4 Troubleshooting and Maintenance MN1269 Servo Systems Co 115 Main Road P O Box 97 Montville NJ 07045 0097 973 335 1007 Toll Free 800 922 1103 Fax 973 335 1661 www servosystems com...

Страница 32: ...op controls the output current proportional to the input voltage VCS Typical applications requiring current mode operation are Web controls Brake applications Bolt tightening Current mode operation is...

Страница 33: ...sted approach using a relay with 4 sets of contacts could be applied as shown in Figure 5 2 providing a power disconnect of motor and servo control in the event of an E stop Figure 5 2 Power Contactor...

Страница 34: ...r injured Step 3 Mount the Chassis Assembly WARNING Do not apply power until all connections are made connections are checked and the safety precautions in Sections 1 are read and understood Step 4 Co...

Страница 35: ...Installation Drawing 115VAC 3 phase input bus power for LD 4 115VAC 1 phase input bus power for LD 2 Servo Systems Co 115 Main Road P O Box 97 Montville NJ 07045 0097 973 335 1007 Toll Free 800 922 11...

Страница 36: ...tor reduces the set values from the specifications in Section 1 Figure B 1 R96 C25 R97 C26 R98 C27 Foldback Current Level LD 3015HS Foldback Current Amps Feedback Resistance Ohms 5 453 7 715 9 1 0K 11...

Страница 37: ...OFF P2 Differential Input 3 2 1 OFF ON P3 Current monitor value DCS 3 2 1 Absolute Actual P4 EC Fault Function 3 2 1 Foldback Latch P6 Amplifier Loop Mode 3 2 1 Velocity Current Potentiometer Settings...

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