Introduction

The external rotor motor offers many attractive features such as space saving, compact design, optimum cooling, full speed controllability, and low starting currents.

Single and three-phase motors are produced to the highest International Quality Assurance Standards.

Sealed-for-life ball bearings are fitted throughout the range with a life expectancy of approximately 40,000 hours, depending upon conditions of operation.

Temperature Range

The motors are designed to operate in the ambient temperature range of -40°C to +40°C, but external rotor motors are often capable of operating in higher ambient temperatures. If you require such conditions, refer your enquiry to one of our sales offices.

Enclosure Standard

The minimum is IP44 in accordance with DIN40050 and AS 1939:1990.

Special Features

Speed Control

External rotor motors are inherently suited to speed control using either electronic or auto-transformer controllers. Refer to page L-1 for details of the range of controllers available.

Care must be taken when selecting speed controllers as the amperage drawn by some motors when being speed-controlled can exceed the rated full load amps. This characteristic is more apparent at approximately 70% of full speed and must be considered when selecting the controller to ensure the controller rating is sufficient for all conditions.

While the drawn amps may exceed the nominal nameplate amps, there is little likelihood of damage to the motor. The overload should be sized to accommodate the excess amperage.

A number of identical fans can be controlled from a single controller, but the total amps of all the motors must not exceed 85% of the controller rating.

Star/Delta Motors

Most three-phase external rotor motors used with backward-curved centrifugal fans are fitted with 2-speed star/delta motors as standard.

These motors enable full speed to be obtained when connected in delta and a reduced speed when connected in star. The ratio of the speeds obtained is 1.3:1 (reduced speed in slip), which approximates to a slightly higher speed than the next synchronous speed down.

These speeds can be obtained by connecting directly to either delta or star. Alternatively, by using a star/delta switch, either speed can be obtained at will. Details of this product are given on page L-1.

Explosion-proof motors do not have the star/delta 2-speed feature and must be connected in star.

Thermal Contacts

Thermal contacts are fitted as standard to all external rotor motors, except those designed for explosion-proof (Ex e) applications.

Embedded deep in the windings of the motors, the contacts are bi-metal cutout design, which are temperature-dependent. Should the temperature of the motor rise to the limit, the bi-metal cutouts activate and cut off the power, thereby providing full protection to the motor.

Re-starting the motors is achieved by two methods:

• Auto-reset
• Manual-reset

The ‘auto-reset’ will permit the fan motor to automatically re-start when the windings cool down. It is recommended that they be connected to a current control relay.

The ‘manual-reset’ type requires the thermal contacts to be wired to a remote trip contactor, which has to be reset manually.

The data sheets for each product detail which type of thermal contact is fitted.

Supply Voltage

As the speed of external rotor motors can be controlled by varying the applied voltage, they can be used where the voltage varies from the standard of 240V/1ph/50Hz or 415V/3ph/50Hz without detrimental effect to the motor. Indeed, on voltages as low as 200 volts on single-phase, or 346 volts on three-phase supply, only a slight reduction of the motor speed would be detected.

Tropic-Proofing

Tropic-proofing consists of an anti-fungal treatment of the windings. Further modifications may be necessary for high-humidity applications.

Explosion-Proof

The explosion-proof external rotor motors offered in this catalogue are only available for three-phase supply. All have a Certificate of Conformity issued under the AUS Ex Certification Scheme for Explosion Protected Electrical Equipment. Refer to page N-7.

Warranty

Note that the warranty is void if the thermal contacts are not used.

AS/NZS3000:2000 wiring rules state that motors required to run unattended shall be fitted with over-temperature devices such as thermal overload relays. If this is not complied with, the warranty will be void.

A licensed electrical contractor or engineer experienced in motor protection should be engaged to assess the motors and specific requirements of the installation.

Introduction

Constructed to appropriate Australian, European and International Standards, standard motors are used to drive a range of fans extending from window and wall units to large industrial axial flow and centrifugal fans.

Standards

The standard motors used are foot, flange or pad mounted, metric type and totally enclosed as produced by most of the world’s major manufacturers. They will run continuously with the minimum of attention and have been selected for their universal interchangeability and availability in countries throughout the world. The motors comply with the appropriate British, Australian and International Standards as far as:-

• Output
• Performance
• Dimensions
• Minimum energy performance standard (MEPS) to AS/NZS1359.5:2000

are concerned.

Temperature Range and Altitude

In general the motors can operate in ambients from -30°C to +40°C at altitudes up to 1000 metres above sea level. Motors to operate outside this range can be supplied if required.

Enclosure Standard

The minimum is IP54 in accordance with the appropriate standards. IP55 enclosure can be supplied for fully weatherproof applications.

Finish

TStandard finish is enamel paint top coat on suitable primer to give good appearance and protection for general usage. Alternative finishes such as epoxy coating can also be provided.

Speed Control

Certain sizes of single and three-phase motors are suitable for variable speed control.

Bearings

Unless otherwise nominated, all fans are fitted with ball or roller bearings. The bearing housing of motors up to frame size D132 as a minimum, are fully enclosed, sealed-for-life and therefore do not require maintenance.

Bearings are pre-packed with grease and, under normal circumstances, last for several years.

Larger frame sizes are fitted with lubrication nipples. When these motors are fitted to axial flow fans, lubricators, extended to the outside of the fan casing to facilitate lubrication, are optional. Grease relief valves must be fitted when extended lubrications are fitted.

Electrical Supply

Motors are generally wound for 415V/3ph/50Hz or 220-240V/1ph/50Hz, however, we can provide motors wound for all voltage and frequency variations.

Insulation

Insulation to Class F with Class B temperature rise is used throughout, allowing for operation in ambients up to +40°C. Motors for higher temperatures can be provided upon request.

Tropic-Proofing

Tropic-proofing consists of an anti-fungal treatment of the windings. Further modifications may be necessary for high humidity applications.

Multi-Speed Motors

Many applications require maximum design conditions only for short periods, leading to wasted energy and high running costs. To address this, fans can be supplied with 2-speed motors.

A wide range of motor speed combinations can be provided, based upon the motor synchronous speeds.

Using this method, power savings can be substantial, as well as generating much lower noise levels.

Thermal Protection

Thermal protection in the form of thermistors can be incorporated in any of the squirrel cage induction motors on request.

Thermistor overloads must be used in conjunction with these motors.

High-Temperature Applications

When continuous operation in higher ambients is essential, the motor can be wound with Class H insulation.

The maximum continuous ambient temperature for Class H insulation is:

• Class H - 80ºC

The above figure is a guide only as the maximum ambient depends upon the load being applied to the motor and the temperature rise of the motor.

If in doubt, refer to our sales office.

Smoke Spill Applications

Refer to page C-6.

Types of Motors

The following are the main groups of motors used in hazardous locations, but not all situations are covered. Should you have an application not covered by the following, please refer to one of our sales offices.

• Ex d - Flameproof motors for industrial use
• Ex e - Increased safety motors
• Ex n - Non-sparking motors
• D.I.P. - Dust ignition-proof motors

Compliance to Standards

All motors suitable for use in hazardous areas are manufactured/modified in strict accordance with the conditions required by the relevant standards and the issued Certificate of Compliance, and are fully tested prior to despatch by the manufacturer.

Selection of Motors for Hazardous Areas

There are a number of defined hazardous areas covering gases and dusts. It is therefore strongly recommended that the relevant Australian Standards and Statutory Authorities be consulted prior to final selection of the motor.

Hazardous Areas Classification

Many gases, vapours and dusts which are generated, processed, handled and stored in industry are combustible. When ignited they may burn rapidly and with considerable explosive force if mixed with air in the appropriate proportions.

Areas where gases, vapours, dusts and fibres occur in dangerous quantities are classified as HAZARDOUS. Classification of areas are:-

• Class I - Gases, vapors, mists
• Class II - Dusts

Gas groupings are further defined for either:-

• Group I - Coal mining (Methane)
• Group II - Other industries

With Group II gases, they are further subdivided into sub-groups IIA, IIB, IIC, depending upon the ignition point of the gas.

ZONAL CLASSIFICATION is also required where explosive gas atmospheres are present and they indicate the probability of the presence of a flammable, combustible or explosive material, the extent, dimension and shape of the hazardous areas, together with the volume in which the hazardous material can be expected. There are three zones:-

• Zone 0 - An area in which an explosive gas atmosphere is continuously present or is present for long periods of time.
• Zone 1 - An area in which an explosive gas atmosphere is likely to occur in normal operation.
• Zone 2 - An area in which a gas atmosphere is not likely to occur in normal operation and if it does occur, it will exist for a short period only.

Temperature Classification

Hot surfaces can cause ignition of gases, vapours and dust, therefore it is necessary to ensure that the maximum surface temperature of equipment introduced into a hazardous area does not exceed the ignition temperature for the gas, vapour or dust in the hazardous area.

Group I Gases: Maximum surface temperature of 150°C

Group II Gases and Class II Dusts: are given a Temperature Class (T) based on the maximum surface temperature of the equipment.

Note: For Ex d flameproof apparatus the external surface is the measured surface. For other types of protection (e.g. Ex e) internal surfaces are of equal importance if the explosive atmosphere has access to them.

Flameproof Motors (Ex d) for Industrial Use

Three-Phase Motors:

These motors are certified to Ex d and can fit a wide range of products as shown throughout the catalogue. The motors are certified to Ex d Class 1, Zone 1 protection. The certificate covers gas groups IIA and IIB, temperature classification T4 and enclosure protection IP56

The Standards complied with are AS2380.1:1989, AS2380.2:1991 and AS1939:1990

Single-Phase Motors:

Fans with single-phase Ex d motors are featured on pages F-4,5 and 8. These fans are certified to Ex d Class 1, Zone 1 protection. The certificate covers gas groups IIA, IIB and IIC, temperature classification T6 and enclosure protection IP66.

The Standards complied with are IEC 60079-0:1998, IEC 60079-1:2001 and IEC 60529:1989.

Explosion-Proof Motors (Ex e) – Increased Safety

Standard Three-Phase Motors:

These motors are certified to Ex e and can fit a wide range of products as shown throughout the catalogue. These motors are certified to Ex e Class 1, Zone 1 protection. The certificate covers gas groups IIA, IIB and IIC, temperature classification T3 and enclosure protection IP66.

The Standard complied with is AS2380.1:1989. This Standard means the motors are also suitable for Ex n and DIP applications.

External Rotor Three-Phase Motors:

These motors are fitted to a range of fans covered in Section F of this catalogue. The motors are certified to Ex e Class 1, Zone 1 protection. The certificate covers gas groups IIA and IIB, temperature classification T3 and enclosure protection IP44.

The Standards complied with are AS2380.1:1989 and AS2380.6:1988.

Electrical and Mechanical Specification

Limiting Temperature

The temperature of an external or internal surface to which the surrounding atmosphere has access, shall not exceed the LIMITING TEMPERATURE specified.

Range

It is possible variations will arise in the kW/frame size/rpm, from one manufacturer to another from that normally referred to in normal motor standards.

Fans for Ex d and Ex e Applications

Fans for Ex d and Ex e applications, or indeed any hazardous application, can be constructed of special materials and incorporate special features.

Anti-static impellers and earthing leads are just some of the features we can provide.

Introduction

Electrical supply, while generally very reliable, is subject to influences that can result in inadequately protected motors being damaged.

As the heart of the motor is the windings, we need to protect the windings from failure.

During normal operation, thermal, mechanical, and electrical stresses can be encountered by motors.

Possible Problems

Refer to page P-1 in the Fan Trouble Shooting section for a list of possible problems and solutions.

Protection Devices

There are motor protective devices available which detect a range of abnormal conditions and automatically switch off the motor.

Different protective devices and the conditions they protect are:

Fuses

• Short circuit between phases or earth
• High current overload

Thermal Overload Relays

• Current overload
• Start-up problems
• Stalling
• Phase imbalance (three-phase motors)
• Over-temperature
• Phase loss (single-phasing of three-phase motors)
• Under-voltage
• Incorrect phase sequences (three-phase motors)

Thermistors and Thermal Contacts

• Over-temperature of the windings

Warranty

Note that warranty is void if the thermal contacts are not used.

AS/NZS3000:2000 wiring rules state that motors required to run unattended shall be fitted with over-temperature devices such as thermal overload relays. If this is not complied with, warranty will be void.

A licensed electrical contractor or engineer, experienced in motor protection, should be engaged to assess the motors and specific requirements of the installation.

Introduction

Low-voltage, permanent magnet DC brush motors are suitable for situations where power is supplied by battery, solar, or generated systems.

Temperature Range & Altitude

These motors are suitable for operating in ambients ranging from -10°C to +60°C at altitudes up to 1000 metres above sea level.

Enclosure Standard

The motor enclosure standard is IP44 in accordance with the appropriate Standards.

Materials & Finish

The motor end shields are natural aluminium and machined from solid bar. The motor body and integral feet are of steel and have a powder coat finish.

Electrical Details

Motors are suitable for 12, 24, or 48V ± 5% DC (direct current) supply.

Insulation

Motor insulation is Class F with a 60°C winding temperature rise. Insulation varnish is two-pack epoxy type, for extended life.

Bearings

Motors are fitted with sealed-for-life ball bearings; the approximate bearing life is 10,000 hours, subject to the operating environment.

Brushes

The motor carbon brushes are easily accessed via screwed caps mounted on each side of the rear end shield. Brush life is approximately 3000 hours, subject to the operating conditions.