Nominal Values

What are nominal values?

They are the average values of actually measured data.

Catalogs give nominal values for the rated current, rated input, rated rotational speed, flowrate, maximum flowrate, maximum static pressure, and noise.

Axial Fans: Inlet and Outlet

What are the meanings of inlet and outlet?

As shown in the following diagram, the side with the label attached is the outlet, and the opposite side is the inlet. The Fan can be installed with either side facing forward, but there is a greater chance of dust entering the Fan when the inlet side faces forward, which may necessitate a filter or other dust-preventive measure.

The inlet and outlet sides of Box Fans are specified for each model.

Precuations for Wiring an Axial Fan

What precautions are necessary for wiring an Axial Fan?

Install a breaker onto the power supply line in order to prevent other equipment from being affected by short circuit accidents of the fan.

Do not connect its power line with power lines of other Axial Fans or other devices in series. Otherwise, it may cause malfunction or burn injury due to the voltage applied exceeding the working voltage. Be sure to connect them in parallel.

Axial Fan: Insulation Level

What are insulation levels?

There are six insulation levels in all, each with a maximum allowable temperature. Safety standards each specify the applicable insulation level.

Axial Fan: Precaution for Building Fans into Equipment

What precautions are necessary for installing products?

Install a guard fence/net or the optional finger guard onto an area where an Axial Fan is installed.

Do not use a box fan without a finger guard. Otherwise, contact to the fan blade may cause injury.

Finger guards are available as the Optional Accessory "R87F-FG" which is selectable according to the size of an Axial Fan to be used.

Be sure to turn off power and confirm that fan blades stop moving before checking the operation or changing filters. Otherwise, contact to the fan blade may cause injury.

AC Axial-flow Fan Accessories

What accessories are available for the R87F and R87T AC Axial-flow Fans?

Please refer to the following diagrams and table.

Use accessories 1, 2, or 3 according to your application.

Axial Fan: Finger Guard and Filter Mounting

Should you mount the Finger Guard and Filter on either the label side of the Axial-flow Fan or on the opposite side depending on whether the inlet side or the outlet side is mounted facing forward?

Exhausting Air from the Outlet

As shown in the following diagram, a Finger Guard must be mounted on the front (label) side of the Axial-flow Fan to prevent an operator from being injured from outside the panel. When installing the Fan on a panel door, another Finger Guard must also be mounted on the rear side of the Fan when there is a possibility that an operator's finger might touch a fan blade from the rear of the Fan when the panel door is being opened or closed.

Taking Air in Through the Inlet

As shown below, a Finger Guard must be mounted on the rear side of the Axial-flow Fan to prevent an operator from being injured from outside the panel. Similar to the case when exhausting air from the outlet, when installing the Fan on a panel door, another Finger Guard must also be mounted on the front (label) side of the Fan when there is a possibility that an operator's finger might touch a fan blade from the front of the Fan when the panel door is being opened or closed.

Protect Axial Fan from Burning

How can you protect Axial-flow Fans from burning?

All OMRON Axial-flow Fans are provided with either impedance protection or thermal protection.

UL, CSA, EN, and IEC standards require all equipment that uses a motor to be equipped with a device that protects the motor against overloads.

Axial Fans: Thermal Protection

What is thermal protection?

• Thermal protection is a method of fan motor protection that is activated when a motor operating at the rated voltage locks up for some reason with the power still being supplied. It uses a thermal relay inside the motor to break the circuit to the winding coil at a temperature below the level that would cause burning.
• The thermal relay is connected in series with the coil and operates by detecting the temperature of the winding coil.Interruption temperature: Approx. 140°C.Reset temperature: Approx. 100°C
• OMRON uses thermal protection on Axial Fans with diameters of 150 mm. (Ordinarily, this method is used for large Fans that cannot be sufficiently protected by impedance protection.)

Do not use the Fan at a temperature or voltage that exceeds the operating temperature or operating voltage. Even with thermal protection provided, the winding will be damaged if the Fan is used when the specified operating temperature or operating voltage is exceeded.

Methods to Extend Lifetime of Axial Fan

Are there any specific application methods that will extend the life of an Axial-flow Fan?

Yes, the following methods will help extend the lifetime.

1. Keep the ambient temperature (i.e., temperature of the Fan itself) as low as possible. → Use the Fan at the inlet.
2. Do not subject the Fan to shock. (The bearing is especially susceptible to damage from shock and has a major effect on the Fan life.)
3. As much as possible, do not expose the Fan directly to dust and other airborne particles. → Install a filter.

Axial Fan: Lifetime

How do you define the service life of an Axial Fan?

The service life of an Axial Fan is generally determined by the bearings.

The following diagram is a simple, mechanical illustration of the Fan structure.

The Fan blade will turn smoothly if the bearings are in normal condition. When there is an abnormality in the bearings, however, the friction between the shaft and the bearings will increase until the blade eventually stops turning.

This is the definition of a Fan's service life.

Axial Fan: Impedance Protection

What is impedance protection?

• This is a method for protecting fan motors from burning that is activated when a motor operating at the rated voltage locks up for some reason with the power still being supplied. It raises the impedance (AC resistance) of the motor windings to suppress increases in current and keep the motor temperature from rising above a preset level.
• UL standards, which stipulate no burning and a winding temperature of 150°C maximum after the motor is operated in a locked condition for 15 continuous days, are used as safety standards.
• Impedance protection is used on OMRON Axial-flow Fans that have a diameter of 120 mm or smaller.

Axial Fans: Replacement Guidelines

When is an Axial Fan estimated to be changed?

In actual use, an Axial Fan must be changed before stopping turning.

Since some changes appear when it comes to the end of its life, be sure to check the following points regularly.

1. Decrease in number of turning
2. Noise increase
3. Abnormal noise generation

Axial Fan: Flow Rate

What is the flowrate?

This is the amount of air that passes through the Fan in a certain time (1 min). In other words, it is the amount of wind that the Fan produces.

Unit: Q (m3⁄min)

Axial Fan: Cooling Effect

Do both inlet and outlet installations have a cooling effect?

Effectiveness is determined by the number and positions of heat-generating objects.

Axial Fan: Maximum Flow Rate

What is the maximum flowrate?

This is the flowrate of the Fan when the static pressure is set to 0 Pa with a flowrate meter. In other words, it is the flowrate when the Fan is operating in a hypothetical state completely free of resistance.

Unit: Qmax (m3⁄min)

Axial Fan: Static Pressure

What is static pressure?

The pressure difference across the front to the back of the Fan generated by the discharged air, which is unaffected by air flow speed.

Unit: Ps (Pa)

1. The air pressure across the front to the back of the Fan does not change when the Fan is stopped.
   
2. Static pressure (Ps) is generated at the front of the Fan when it rotates.
   

Axial Fan: Maximum Static Pressure

What is the maximum static pressure?

The pressure difference inside and outside the Unit when the flow rate is adjusted to zero (0 m3/min.) at the flow measurement unit. This would be the pressure in front of the Unit when the front of the fan was completely sealed.

Unit: Ps max. (Pa)

Difference between R87F and R87T Axial Fan

What is the difference between the AC Type Axial Fan "R87F" and "R87T"?

Refer to the following comparative chart.