BECKHOFF AM8xxx Motor Guide

BECKHOFF AM8xxx Motor Guide

In the transformation of automation drive systems or the development of new equipment, the selection and installation of servo motors directly determine the dynamic performance and long-term reliability of the equipment. The Beckhoff AM8000 and AM8500 series synchronous servo motors cover a wide range from extremely low torque (0.2 Nm) to high torque (129 Nm), with flange sizes ranging from 40 mm to 194 mm, and support for multiple feedback systems (Resolvers, OCT single/multi turn, Hiperface) as well as options such as holding brakes, shaft seals, and forced air cooling. This article is aimed at on-site engineers, systematically sorting out the model meaning, technical parameters, mechanical installation, electrical wiring, brake use, power derating, and common fault troubleshooting of AM8xxx motors, helping you quickly complete selection and deployment in replacing old motors (such as Woodward, Honeywell, and other discontinued models) or new projects.

Model interpretation and selection framework

The order number for AM8xxx motors follows a strict structure: AM8 t u v-w x y z-a 00 0. Taking AM8032-1G10-0000 as an example:

AM8: Synchronous servo motor product series.

t: Motor series -0 is the standard inertia, 5 is the high inertia (AM85xx).

u: Flange dimensions -1=40 mm, 2=58 mm, 3=72 mm, 4=87 mm, 5=104 mm, 6=142 mm, 7=194 mm.

v: Total length -1 to 4 represents different stack lengths.

w: Shaft end form -0=optical axis, 1=with keyway and half key, 2=with IP65 shaft seal ring optical axis, 3=with IP65 shaft seal ring and keyway.

x: Winding types - A... Z, commonly used B, C, D, E, etc.

y: Feedback System -0=Resolver (14 bits), 1=OCT Single Loop 18 bits, 2=OCT Multi Loop 18 bits, A=OCT Single Loop 23 bits, B=OCT Multi Loop 23 bits, G=OCT Single Loop 24 bits SIL2, H=OCT Multi Loop 24 bits SIL2, 3/4=Hiperface Single Loop/Multi Loop 18 bits.

z: Maintain braking -0=no braking, 1=24 V braking.

a: Version -0=Standard.

Core selection parameters: First, determine the flange size and length based on the load inertia ratio, required rated torque, and speed, then select the winding (which affects the rated current and speed), and finally select the feedback according to the accuracy requirements. For vertical axis or scenarios that require power-off locking, a hold brake must be selected, but it should be noted that the brake is only used for holding and is not suitable for dynamic braking.

Technical Parameters Essentials

Taking commonly used models as an example (data based on 40 ° C ambient temperature, winding temperature rise of 100K):

Model: Flange static torque M ₀ (Nm), static current I ₀ (A), maximum speed (rpm), rotor inertia (kgcm ²), braking holding torque (Nm)

AM8011 40 0.20 0.76 10000 0.03 0.6

AM8022 58 0.80 1.50 12000 0.26 2

AM8032 72 2.38 2.95 10000 0.85 2

AM8042 87 4.10 4.10 9000 1.98 9

AM8052 104 8.20 6.30 9000 4.09 9

AM8062 142 21.10 12.40 6000 20.0 20

AM8072 194 54.60 20.60 5000 92.2 70

Winding selection: Multiple windings can be provided for the same motor length (e.g. AM8022 has 21B, 21D, 22D, 22E, 23E, 23F). Low current windings (such as 21A) are suitable for 115V or 230V power supply, while high current windings (such as 23F) can achieve higher torque but require larger peak current. When selecting, the rated current of the driver should not be less than the electrostatic current I ₀ of the motor, and the peak current should not be less than I ₀ max (usually 5 times I ₀, and 3 times AM806x and above).

Temperature protection: All motors (except AM801x) are equipped with LPTC-600 temperature sensors (equivalent to KTY84-130). 120 ° C warning and 140 ° C shutdown must be configured in the servo drive, otherwise the motor may demagnetize due to overheating.

Key points of mechanical installation

3.1 Flange installation

Use internal hexagon screws that comply with DIN EN ISO 4762 strength grade 8.8. Tightening torque:

AM801x：M4 × 16 → 3.4 Nm

AM802x：M5 × 16 → 5.5 Nm

AM803x：M5 × 16 → 5.5 Nm

AM804x：M6 × 20 → 10 Nm

AM805x：M8 × 25 → 25 Nm

AM806x：M10 × 30 → 50 Nm

AM807x：M12 × 40 → 85 Nm

Attention: Do not apply impact to the motor shaft during installation. Impact can damage the optical encoder (OCT/Hiperface) and cause concentricity deviation. The coupling or pulley must be disassembled using a pulling tool, and striking is strictly prohibited.

3.2 Axle end load

The allowable radial force F ᵣ and axial force F ₐ on the motor shaft are related to the speed. When using pulleys or gears, the radial force application point should be as close to the flange surface as possible. Excessive axial force can shorten the bearing life and cause the brake to remain stuck. The Beckhoff official website provides a "load/force calculator" for quick verification.

3.3 Installation direction and sealing

The standard installation position is IM B5 (horizontal, flange installation). When installing IM V3 (axis vertically upward), liquid may accumulate on the flange surface and seep into the interior of the motor due to capillary action. Even with the optional shaft seal ring (IP65) and sealed air interface, it is still recommended to drain regularly. For situations with splashing water or high dust, models with radial shaft seals (w=2 or 3 in the model) and sealed air connections (w=4 or 5) must be selected.

Electrical connection and cable selection

4.1 Connector Types

AM801x~AM803x: iTec connector (rotatable, 330 °)

AM804x~AM806x (to P winding): M23 Speedtec connector

AM806x (starting from Q winding) and AM807x: M40 Speedtec or terminal box

4.2 Power and Feedback Pin Allocation (Taking M23 as an Example)

Pin signal function

A U motor phase U (black/1)

B V motor phase V (black/2)

C W motor phase W (black/3)

PE PE protective grounding (green/yellow)

E Temp -/OCT-Temperature sensor or OCT data - (blue)

F Shield shielding

G Brake+Brake+24 V (Black/5)

H Temp+/OCT+temperature sensor or OCT data+(white)

L Brake - Brake GND (Black/6)

The allocation of iTec connectors is similar, but the brake power supply uses pins 5 and 6, and the temperature signal uses pins 3 and 4.

OCT (Single Cable Technology): Integrating power and feedback into the same cable, transmitting position by superimposing signals. When using OCT, Beckhoff dedicated cables (such as ZK4500-8023-xxxx) must be used, and ordinary encoder cables cannot be mixed.

4.3 Motor Cable Selection Table (AX5000 Drive)

Motor series cable model laying method

AM801x~803x ZK4500-8022-xxxx high dynamic/torsional

AM804x~806x (to P) ZK4500-8003-xxxx fixed installation

Same as above ZK4500-8023-xxxx high dynamic

AM806x (Q/R)~807x ZK4500-8025-xxxx high dynamic

AM807x high current ZK4504-8027-xxxx/ZK4506-8027-xxxx dynamic/fixed

Select ZK4530-8110-xxxx or ZK4510-8110-xxxx for the feedback cable (used for Resolving or OCT). All pre installed cables meet UL and EMC requirements.

Maintain Brake - Safety Guidelines for Use

The brake is a permanent magnet power-off brake with a voltage of 24 V DC (+6%/-10%). After being engaged, the rotor is released. Key parameters:

Release time (t_BRH): The time it takes for the brake to fully engage after a power outage (e.g. 25 ms for AM803x)

Suction time (t_BRL): The time required for complete release after power on (8 ms)

It is strictly prohibited to use the holding brake for dynamic braking (i.e. for deceleration and stopping). During emergency stop, it is allowed to brake up to 2000 times from a maximum of 3000 rpm and with a load inertia not exceeding 3 times the motor inertia. Exceeding this limit will result in excessive wear of the brake pads.

Vertical axis safety: Additional redundant brakes, mechanical counterweights, or fall protection devices must be added. Relying solely on the motor to maintain the brake does not comply with personal safety standards (ISO 13849-1).

Function check: In the power-off state, apply a force of approximately 1.2 times the nominal holding torque to the shaft end with a torque wrench, and the rotor should not rotate. Alternatively, position deviation can be monitored through TwinCAT Scope.

Forced air cooling (fan cover)

AM805x, AM806x, and AM807x can be equipped with an external fan cover (z=A/B/C/D in ordering features). The fan power supply is 24 V DC, power consumption:

AM805x：4.6 W

AM806x：9.8 W

AM807x：31.2 W

After installation, the continuous torque of the motor can be increased by about 30% (see the Mn value of the fan version in the technical data sheet for details). Special control cable ZK4054-6400-0xxx must be used to connect the fan and ensure that the ventilation outlet is unobstructed.

Power derating and high-altitude/high-temperature operation

When the ambient temperature exceeds 40 ° C or the installation altitude is higher than 1000 meters, the rated torque of the motor needs to be reduced.

Temperature derating: 40-50 ° C, with a decrease of approximately 2% (linear) for every 1 ° C increase. For example, f ₜ ≈ 0.8 at 50 ° C.

Altitude derating: For every 1000 meters increase above 1000 meters, the derating decreases by 6% (2000 meters → 0.943000 meters → 0.83).

Comprehensive derating: M ₀ -red=M ₀× f ₜ× f ₕ.

Example: AM8062 has an actual usable static torque of 21.1 × 0.8 × 0.94 ≈ 15.9 Nm at an altitude of 2000 m in an environment of 50 ° C. If this value is exceeded, the motor will overheat.

Common troubleshooting table

Possible causes and solutions for the fault phenomenon

The motor does not start, the brake is not released, the driver is not enabled, and the power supply is out of phase. Check the brake voltage (24 V ± 10%); Confirm the driver enable signal; Measure the resistance of the three-phase winding (should be balanced)

Rough motor operation, abnormal noise, encoder signal interference, bearing damage, and poor mechanical alignment. Check whether the feedback cable shielding is single ended grounded; Auscultation of bearings, if there is a metallic frosted sound, replace the bearings; Re calibrate the concentricity of the coupling

Motor overheating (>140 ° C), excessive load, poor ventilation, high ambient temperature, improper PWM switch frequency setting, reducing load or selecting a higher torque motor; Clean the fan and heat sink; Measure the actual ambient temperature; Reduce the switching frequency of the driver (≤ 8 kHz)

Measure the brake resistance (usually several tens of ohms) by keeping the brake failure coil open, insufficient voltage, and brake pad wear; Check if the power supply line is broken; Replace the brake

Encoder position jump OCT communication interference, connector poor contact inspection cable shielding layer; Re plug and unplug the connector (up to 500 insertions allowed)

Re identify the motor electronic nameplate in TwinCAT Drive Manager due to motor vibration, unstable speed, and inappropriate drive parameters (high gain in current and speed loops); Perform automatic tuning

The installation direction for liquid infiltration at the flange is IM V3, and the unsealed air should be installed horizontally; Or add shaft sealing rings and 0.1 bar sealing air

Maintenance and spare parts

Bearing: It is recommended to replace it after 30000 hours of operation. If there is any abnormal response, stop the machine immediately.

Shaft sealing ring: Check every 5000 hours and lubricate with Mobilgrease FM22. Damage can cause IP65 failure.

Cable: When used dynamically, the bending life is about 5 million times. Check for cracks on the outer skin.

Connector: After rotating the plug box more than 10 times or plugging and unplugging 500 times, it is recommended to replace it to maintain IP65.