Carrier NP034-074 specifications Ð Air Quantity Limits cfm

Table 9B Ð Field-Supplied Evaporator-Fan Pulley Data, 054-074 Units

										BELTS
IFM	IFM	MOTOR PULLEY			BLOWER PULLEY			48 Series and 50 Series				50 Series
								Horizontal Discharge Units			Vertical Discharge Units
Hp	RPM
		No.	Type	Size (in.)	No.	Type	Size (in.)	Quantity	Type	Size (in.)	Quantity		Type	Size (in.)
		Grooves			Grooves
	450						18.5			118				132
	470			4.3			16.1			115				125
15	485	2	B5V		2	B5V	15.5	2	5VX		2		5VX
	575			4.5										123
	650			5.1			13.7			112
	725			5.7
	405						18.5			123				132
	470	3		4.3	3		16.1	3		118	3			125
20	485		B5V			B5V	15.5		5VX				5VX
	575			4.5
	660	2		5.1	2		13.7	2		115	2			123
	725			5.7
	405						18.5			123				132
	470	3		4.3	3		16.1	3	5VX		3			125
25	485		B5V			B5V	15.5						5VX
	575			4.5						115				123
	700	2		5.5	2		13.7	2	B5V		2
	725			5.7
	470	4		4.3	4		16.1	4			4
	485						15.5
30	530	3	B5V	4.7	3	B5V	15.5	3	5VX	118	3		5VX	123
	600			5.5
	660	2		5.9	2		15.5	2			2
	730			6.5
IFM Ð	Indoor (Evaporator) Fan Motor

Check rotation of wheel with arrow on the fan housing. Check fan speed with a strobe-type tachometer, or use this formula:

Fan	=	motor rpm x motor sheave pitch diameter (in.)
Rpm
		fan sheave pitch diameter (in.)

(Obtain motor rpm from the fan motor nameplate and read sheave pitch diameters marked on the fan and motor sheaves.)

Example:
Nameplate motor rpm	1760
Motor sheave pitch diameter (in.)	6.4
Fan sheave pitch diameter (in.)	12.4

Fan Rpm = 1760 x 6.4 = 908 Rpm 12.4

The maximum allowable fan speed for the supply-air fan is 900 rpm for 034 and 044 units and 750 rpm for 054-074 units. The maximum rpm for the power exhaust is 1300 rpm for 034 and 044 units and 925 rpm for 054-074 units. Excessive fan speed may result in condensate carryover from the evaporator coil, fan motor overload, or wheel failure. See Table 10 for Air Quantity Limits.

Table 10 Ð Air Quantity Limits (cfm)

UNIT SIZE	MINIMUM	MAXIMUM
034	6,000	15,000
044	8,000	20,000
054	10,000	25,000
064	12,000	30,000
074	14,000	30,000

Condenser Fans and Motors Ð Each unit has mul- tiple condenser fans and motors; these are positioned at the factory. See Fig. 32 for correct location of fan in ori®ce. Check that fan propeller rotation is correct; it should be counter- clockwise when facing the fans. If fan propeller rotation is incorrect, switch motor leads.

Return-Air Filters Ð Check that the correct ®lters are installed in the ®lter rack. See Tables 1A and 1B for quan- tities and sizes. Access is through the door marked FILTER SECTION. Do not operate the unit without return-air ®lters.

Economizer Inlet Screens Ð Check that they are in place before operating the unit.

Economizer Dampers Ð With no power to the unit, the economizer outdoor-air dampers should be fully closed. Check by opening the access door marked FILTER SEC- TION. On units with economizer, be sure economizer mini- mum position is set at the desired setting. Be sure hood is installed properly.

25% Outdoor-Air Damper Ð On units without econo- mizer, be sure 25% outdoor-air damper is set at the desired position. Also, be sure hood is installed properly.

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