Greenheck Fan 129 manual Model Designation, Motor Information Belt Drive Only, DIRECt Drive

Fan Fundamentals

Introduction to FAN SELECTION

This is a guide to the most basic fan sections, all of which enable you to select the right fan for the job. It will answer the following questions (and more):

•What is a SONE?

•How are model numbers and performance tables used to select a fan?

•How are direct drive and belt driven fans different?

•What types of motors are used with these fans?

The goal is to understand and use the Greenheck literature as an important tool in filling a customer’s fan order.

	Terms
cfm	Cubic Feet Per Minute. A measure of airflow.
Ps	Static Pressure. Resistance to airflow measured in inches of water gauge.
sone	A measure of loudness. One sone can be approximated as the loudness of a quiet refrigerator at a distance of 5 feet. Sones
	follow a linear scale, that is, 10 sones are twice as loud as 5 sones.
Bhp	Brake Horsepower. A measure of power consumption. Used to determine the proper motor horsepower and wiring.
hp	Horsepower. Used to indicate a fan’s motor size.
rpm	Revolutions Per Minute. Measure of fan speed.
TS	Tip Speed. The speed of the tip of a fan wheel or prop measured in feet per minute.
AMCA	Air Movement & Control Association. A nationally recognized association which establishes standards for fan testing and
	performance ratings. AMCA also license air volume and sound certified ratings.

Model Designation

For Greenheck belt drive models, the model designation tells the model type, size and the motor hp.

EXAMPLE:	GB-090-6
Model is GB		hp is 1/6
Nominal Wheel Dia. 9 in.

For direct drive units, the model designation tells the model type, the size and the motor/fan rpm.

EXAMPLE:	G-121-B
Model is G		rpm is 1140
Nominal Wheel Dia. 12 in.

BELT DRIVE		DIRECT DRIVE
Suffix	Motor hp	Suffix	Fan rpm
6	1/6	A	1725
4	1/4	B	1140
3	1/3	C	860
5	1/2	D	1550
7	3/4	G	1300
10	1	E	1050
15	11/2	F	880
20	2	P	1625
30	3

505

7571/2

This table lists model designation suffixes for motor horsepower and fan rpm.

Motor Information (Belt Drive Only)

When specifying a belt drive fan, the model designation does not completely describe the unit. Additional information about the motor is necessary. These items are listed below:

Motor Enclosure

This will be either “Open” (open, drip proof), “TE” (totally enclosed) or “EXP” (explosion-resistant). Open is the most common and will be supplied unless otherwise specified.

DIRECt Drive

Selection of direct drive fans (those with the motor shaft connected to the fan wheel or propeller) is nearly the same as belt drive selection. However, there are two differences worth noting. Where belt drive fan speed can be altered by adjusting the motor pulley, direct drive fans (since they have no pulleys) must use a different method.

1To adjust a direct drive fan’s speed (also motor speed) or to provide a means of meeting an exact performance requirement, a speed control can be furnished. Speed controls vary the voltage supplied to the fan and slow

it down; a principle similar to the way dimmer light switches work.

2Models CUE and CW, sizes 060-095 and Model SQ, sizes 60-95, are provided with 115 volt, 60 cycle motors.

Speeds

Motors are available in either single-speed or two speed. Single-speed motors are 1725 rpm. Two speed motors will be 1725/1140 rpm. Single-speed will be supplied unless otherwise specified.

Electrical Characteristics

Voltage and phase. Voltage can be 115, 208, 230 or 460. Phase is either single-or 3 phase. A 115 volt, single- phase motor is shown as 115/1. Typically, motors of 1/2 hp and less are single-phase. Motors of 3/4 hp and greater are 3 phase.

Typical Motor Tag - Electrical Instructions

Suffix Letter	Motor Speed	Wiring Connections
D	1550 rpm	White to L1 Black to L2
G	1300 rpm	White to L1 Blue to L2
E	1050 rpm	White to L1 Red to L2

The three speeds are 1550 rpm (D), 1300 rpm (G) and 1050 rpm (E). Changing a motor lead is all that is necessary to change speeds. When selecting a model with a 3 speed motor, it is recommended that the G speed be chosen whenever possible. This is the middle speed, which gives the greatest flexibility in air volume because airflow can be increased or decreased simply by changing a motor lead.

F A N F U N D A M E N T A L S 129