Model NYB Pre-Starting Belt Tension Checks

Model NYB

Pre-Starting Belt Tension Checks

6.Always loosen tension enough to install belts without stretching, see figure 4.

Belts

		Do not force belt(s). Forcing the
	Figure 4	belt(s) will break the cords and
	Figure 4	cause belt failure
		cause belt failure

7.For units with two groove pulleys, adjust so the tension is equal in both belts.

8.If adjustments are made, it is very important to check the pulleys for proper alignment. Misaligned pulleys lead to excessive belt wear vibration, noise and power loss, see figure 5.

Figure 5

9.Belt tension can be adjusted by loosening four fasteners on the drive frame, see figure 6. This allows the motor plate to slide on the drive frame angles for proper positioning.

Fasteners

(4) *Fasteners

*Identical fasteners on opposing side must also be loosened.

Figure 6

10.Belt tension should be adjusted to allow 1/64 inch (0.397 mm) of deflection per inch of belt span. For example, a 15 inch (381 mm) belt span should have 15/64 inch (0.234 mm) (or about 1/4 inch (6 mm)) of deflection with moderate thumb pressure at mid-point between pulleys, see figure 7.

13.The adjustable motor pulley is factory set for the RPM specified. Speed can be increased by closing or decreased by opening the adjustable motor pulley. Two groove variable pitch pulleys must be adjusted an equal number of turns open or closed.

14.Any increase in speed represents a substantial increase in the horsepower required by the unit.

15.Motor amperage should always be checked to avoid serious damage to the motor when speed is varied.

WARNING

The fan has been checked for mechanical noises at the factory prior to shipment. If mechanical noise should develop, suggested corrective actions are offered in the Troubleshooting section.

IMPORTANT

Over tightening will cause excessive bearing wear and noise. Too little tension will cause slippage at start-up and uneven wear.

Operation: NYD/NYB

1.Before starting or operating fan, check all fasteners for tightness. In particular, check the setscrews in wheel hub (and pulleys, if applicable).

2.While in the OFF position or before connecting the fan to power, turn the fan wheel by hand to be sure it is not striking the venturi or any obstacle.

3.Start the fan and shut it off immediately to check rotation of the wheel with directional arrow in the motor compartment, see figure 3 on page 3.

4.When the fan is started, observe the operation and check for any unusual noises.

5.With the system in full operation and all ductwork attached, measure current input to the motor and compare with the nameplate rating to determine if the motor is operating under safe load conditions.

6.Keep inlets and approaches to fan clean and free from obstruction.

Inspection: NYD/NYB

Inspection of the fan should be conducted at the first 30 minute and 24 hour intervals of satisfactory operation.

Deflection

Figure 7

30 Minute Interval

Inspect bolts, setscrews and motor mounting bolts. Adjust and tighten as necessary.

24 Hour Interval

Check all internal components. On NYB unit only, inspect belt alignment and tension. Adjust and tighten as necessary.

Models NYD & NYB • Tamper-Resistant Centrifugal Roof Exhaust Fans

NYD, NYB specifications

Greenheck Fan has long been known as a leader in the HVAC industry, with a commitment to providing innovative solutions for various ventilation needs. Among their impressive lineup, the NYB and NYD series stand out, showcasing advanced engineering, energy efficiency, and robust performance.

The Greenheck NYB and NYD fans are designed specifically for commercial and industrial applications, focusing on building ventilation demands. The NYB series features belt-driven centrifugal fans, while the NYD series brings direct-drive technology to the table. This versatility allows these fans to accommodate a wide range of air handling applications, from exhaust to supply air scenarios.

One of the main features of the NYB series is its ability to handle high volumes of air at modest static pressures. This performance characteristic is ideal for environments such as warehouses, factories, and large commercial spaces where air turnover is crucial. The NYD series, on the other hand, excels in applications requiring quieter operation and reduced maintenance, thanks to its direct-drive design, which eliminates the need for belts and pulleys.

Both the NYB and NYD fans come equipped with several advanced technologies designed to enhance their efficiency and reliability. For instance, they often incorporate energy-efficient motors that comply with or exceed regulations set by agencies like the Department of Energy (DOE). This focus on energy efficiency not only reduces operational costs but also supports sustainability in building operations.

Durability is a key characteristic of both series, with robust construction materials that ensure longevity even in demanding environments. The fans typically feature heavy-gauge steel housings and high-quality coatings that resist corrosion, thereby extending their service life.

Moreover, these fans can be customized with various accessories, including adjustable dampers, filters, and sound attenuators, enabling them to meet specific application requirements. The easy installation and maintenance features add to their appeal, allowing for seamless integration into existing systems.

In summary, the Greenheck Fan NYB and NYD series represent cutting-edge options for any commercial or industrial ventilation system. Their combination of energy efficiency, advanced technologies, durability, and customization makes them a go-to choice for professionals seeking reliable and effective air management solutions.