External Brake Resistor - AX2090-BW5x-xxxx

Appropriate use

The brake resistors from the AX2090-BW5x-xxxx series are exclusively designed for direct application with an AX5000 series servo drive or the AX5021 brake module. They are designed for installation as components in electrical installations and machines together with the servo drive or the brake module, and this is their only purpose.

Scope of supply

The scope of supply includes the following components:

• Brake resistor from the required performance class
• Technical documentation
• Packaging

If one of the components is damaged, please notify the logistics company and Beckhoff Automation GmbH immediately.

Safety rules

The responsible staff must ensure that the application or use of the products described satisfy all the requirements for safety, including all the relevant laws, regulations and guidelines.

NOTICE
	UL-Listing! It is essential to observe chapter "Product overview-->Guidelines and Standards-->UL-Listing" if you wish to operate an AX5000 in an economic area that requires a UL-Listing.

Product description

The external brake resistors of the AX2090-BW5x-xxxx series are able to convert the dynamic energy generated during braking of a servomotor into heat. The series covers a wide continuous power and peak power range. The built-in temperature switch enables the system to respond immediately to any overload of the brake resistor through analysis in the AX5000 or the PLC. All brake resistors of the AX2090-BW5x-xxxx series are UL and CSA approved.

Type key

Dimensions and technical data

*) 4% output reduction per 10 K temperature difference

Mounting positions and distances

(A) = vertical installation is only permitted according to the diagram (terminal box facing downwards).
(B) = horizontal installation

For all mounting positions the following minimum distances must be adhered to:

200 mm to adjacent components, walls etc. and 300 mm to components, ceilings etc. above. If the device is installed vertically (A), the minimum distance to components, floors etc. below is 200 mm to allow unobstructed flow of air to the brake resistor.

Electrical installation

Remove the two screws (1) and remove the cover (2) in direction of the arrow. Connect an adequately dimensioned cable (see section Cables) to the terminals (3) of the resistor and the earthing stud (5) and take it out of the terminal box through the strain-relief assembly (9). Ensure adequate strain relief with the two screws (8). Connect the other side of the cable to the DC link contact connector X2 (10) of the AX5000. The connector is supplied with the AX5000. Connect the earthing cable to the earthing conductor of the control cabinet.

Connect an adequately dimensioned cable to the potential-free N/C contact (4) of the temperature switch and take it out of the terminal box through the strain-relief assembly (7) (see section Temperature switch). Ensure adequate strain relief with the nut (6).

Install the cover (2) in reverse order.

Cables

We recommend Beckhoff motor cables for connecting the brake resistors.

We recommend wire end sleeves.

Temperature switch

The temperature switch has a potential-free N/C contact, which enables immediate response to any overload of the brake resistor through analysis in the AX5000 or the PLC. Connect the cable directly to a free input of plug "X06". Then parameterize it such that the AX5000 stops the motor(s) with an emergency ramp or the PLC reads and processes this input.

Short-term capacity

Brake resistors are usually not operated continuously, but only exposed to short-time duty. In the following section the permitted short-term capacity is calculated based on the continuous power, overload factor and duty cycle.

Duty cycle

The duty cycle is a relative value that depends on the switch-on time (ton)and the cycle time. Cycle times up to 120 sec. are used directly in the calculation. Should the cycle time exceed 120 sec., the maximum relevant cycle time of 120 sec. is used in the calculation.

Overload factor

Calculation formula:

Short-term capacity = continuous power x overload factor

Overtemperature and continuous power at 100% duty cycle

If your application requires a higher continuous power than the specified nominal capacity, you can accept this state if a higher brake resistor temperature is permitted. The following diagram shows the overtemperature v. the continuous power.