Frequently Asked Questions
Do I need to call before I send in a product for repair or return?
Yes. All Return and Repairs require that a Return Materials Authorization (RMA) number be generated to track the transaction. You can call our Customer Service Dept., or download an
RMA Request Form. Product returned without a RMA# will NOT be processed. Typical repairs will take 10 business days. Gearboxes may take up to 45 days. Motors are not repairable. Anaheim Automation charges a "flat-rate" repair fee for products not covered under warranty, regardless of the problem found.

What is the warranty period for Anaheim Automation products?
The warranty period is 12 months from the date of the invoice or 18 months from the date on manufacture, whichever comes first. The warranty is void if the failure was caused by misuse, neglect, mis-wiring, or due to modification. See our full Terms and Conditions on our web site.

Can I buy components to fix a board?
No. You void product warranty when you perform your own repairs. We prefer that you send Anaheim Automation the board so our qualified technicians can test and resolve any issues found evident in the board.

What is the difference between a 4 wire and a 6 wire motor?
A 4 wire motor has 2 leads per phase requiring the motor to only be connected in a bipolar series. Whereas a 6 wire motor has 3 leads per phase with the center tap of each winding as the common. With 6 wires, the motor can be connected in Bipolar Series, Bipolar Half-Coil or Unipolar.

What is the difference between a 4 wire and a 8 wire motor?
A 4 wire motor has 2 leads per phase and can only be connected in a bipolar series. Whereas a 8 wire motor has 2 leads per phase but also splits the 2 phases into 4 phases. With 8 wires, the motor can be connected in Bipolar Series, Bipolar Half-Coil, Bipolar Parallel, or Unipolar giving the user the connection choice for the optimum torque vs speed setup they require.

What is the difference between an AC Servo and a DC Servo?
A DC servo motor uses a DC Brush motor and PWM control circuitry to vary the current through a single phase. An AC servo motor uses a BLDC motor and controls the motor through sinusoidal currents of three phases. DC servo motors contain brushes and are thus prone to maintenance every 2000 hours of operation where the AC servo motor are brushless motors and thus do not have the maintenance issues. DC servo motors though do not have complex control circuitry required that the three phase AC servo motors need.

What are the advantages of Magnetic Rotary Encoders over Optical Rotary Encoders?
Some of the advantages of Magnetic Rotary Encoders over Optical Rotary Encoders are the following:

1. Are not susceptible to various contaminants such as dirt, dust and moisture
2. Not vulnerable to light exposure
3. Greater reliability and durability

What is the best way to test AC Motors?
1. If high current is being drawn from the motor, it may indicate a bent shaft or an issue with the motor bearings. Remove power from the motor system. If needed, switch off the circuit breaker connected to the unit to prevent injury.

2. For AC Motors using Start-Up Capacitors:
If the motor makes a humming sound, fails to rotate under the full load and produces high current it may be a bad start up capacitor. If the capacitor is of a large value, wait 30 minutes to an hour to allow some of the charge to dissipate. After doing so, discharge the remaining charge stores in the capacitor by shorting out the terminals together with an insulated screwdriver. While holding the plastic insulated handle, place the tip of the screwdriver against one of the terminals and come across with the screwdriver shaft to make a connection with the other terminal. A small or big spark may be seen depending on the amount of charge remaining in the capacitor. Using an Digital Multimeter, measure the resistance across the two terminals. If '0' resistance is read, then the capacitor is shorted and needs to be replaced.

3. To make sure an AC Motor is operating correctly, test the windings of the motor. Using a Ohmmeter (Digital Multimeter) set the resistance reader setting. Touch both leads together to make sure meter reads zero ohms. Next, use the ohmmeter to measure the resistance of each winding (phase). Each winding should have a small resistance and should not be open or indicate a short. If a short is detected then the motor is no longer working properly and must be changed.

What is the best way to test a DC Motor?
The best way to test Brush DC Motors is to place a voltage across the motor leads and see if the motor turns. If the motor rotates, you can check the no load speed and no load current to determine if the motor is operating normally. To check if the motor runs in the opposite direction, change the polarity of the wires, and the motor should rotate in the opposite direction.

What are poles in a Brushless DC Motor?
Poles in the BLDC motors refer to the Magnetic North and South poles in the Permanent Magnet. A 4 pole motor has 2 North Poles and 2 South Poles. The higher the number of poles, the smoother the motor will run.

What is CANOpen?
CANOpen is a communication protocol used in automation because it supports network management, device monitoring and communication between nodes. In reference to the OSI model, CANOpen implements the network, session, presentation, and application. The data link and physical layers are usually implemented by a controller area network(CAN).

What makes a CANOpen device, CANopen?
1. The CANOpen device must have a communication unit that implements messaging protocols so that the device can communicate with other nodes on the network.

2. The starting and resetting of the device must be controlled by a state machine. The state machine must contain the states initialization, pre-operational, operational and stopped. Transitioning between states is possible via a network management communication.

3. The device must have an object dictionary, which is simply an array of variables with a 16-bit index. This 16-bit index is used to configure the device and reflects its environment (i.e. contain measurement data); much like recipe memory!

4. The device must contain an application layer where the device performs the desired functions. Once the state machine is configured, the application will then configure variables in the object dictionary and use the communication layer to transport these variable values to and from the controller.

What is an object dictionary?
The object dictionary is a look up table that contains information that the state machine needs to act on. An example, it could be the desired temperature that a user inputs for a thermostat. An entry in an object dictionary is defined by:

Index, the 16-bit address of the object in the dictionary
Object name, a symbolic type of the object in the entry, such as an array, record, or simple variable. This is data type

Name, a string that describes the object.

Attribute, gives us information on the access rights for this entry, this can be read/write, read-only, write-only or read only.

The Mandatory/Optional field defines whether a device conforming to the device specification has to implement this object or not. This is like a traffic blocker it shall only accept what it needs.

Why is the stepper motor size important? Is it possible to just choose a large motor size?
The stepper motor size is important because if the motor’s rotor inertia predominately consists of the load, resonance increases and poses vibration and acceleration issues. Also, larger rotors require more time to accelerate and decelerate and are more costly. Therefore it is important to choose a motor size dependent on the criteria for user application.

While increasing speed, why do stepper motors lose torque?
Inductance and lack of time for the current to build in the windings is the leading cause for motors losing torque at high speeds. The electrical time constant, τ, is the amount of time it takes a motor winding to charge up to 63% of its rated value given a resistance, R, and inductance, L. With τ = L/R, at low speeds, inductance is not an issue since the current has the time to increase and reach its rated value to flow through the motor windings. However, at high speeds, sufficient current cannot pass through the windings quick enough before the current is switched to the next phase, thereby reducing the torque provided by the motor.

Why does increasing the voltage increase the torque if stepper motors are not voltage driven?
Voltage can be viewed as forcing current through the coil windings. By increasing voltage, pressure to force current through the coil also increases. This in turn causes the current to build faster in the winding and is able to produce a larger magnetic field. This larger magnetic field is what produces more torque.

What temperatures are stepper motors able to run at?
Most stepper motors include Class B insulation. This allows the motor to sustain temperatures of up to 130° C. Therefore, with an ambient temperature of 40° C, the stepper motor has a temperature rise allowance of 90° C allowing for stepper motors to run at high temperatures.

Is it possible to get more torque by running the stepper motor at double its rated current?
It is possible to increase torque by increasing the current but by doing so, it weakens the motor’s ability to run smoother and will also make the temperature of the motor rise. Please make sure to not run the stepper motor above the internal tempearture of its class rating.

What is the difference between four, six and eight leads in motors?
4 and 6 lead stepper motors are considered 2 phase motors. 8 lead stepper motors are considered to be 4 phase steppers. 4 lead motors can be wired in bipolar series connection only 6 lead motors can be wired in bipolar series, bipolar half-coil or uniploar connections 8 lead motors can be wired in bipolar series, bipolar half-coil, biploar parallel or uniploar connections.

What is the difference between Unipolar and Bipolar motors?
A unipolar wound motor has six lead wires with each winding having a center tap. Most applications implementing unipolar wound motors require high speed and torque. On the other hand, a bipolar wound motor has four lead wires with having no center tap connections. Most applications implementing bipolar wound motors require high torque at low speeds.

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