Carrier 50HE003-006, 50HJ004 installation instructions + Tr

50HE,HJ

																						85		90	95	100		105	110
																						(29)		(32)	(35)	(38)		(41)	(43)
																			46
CONTROL	CONTROL POINT																4
CURVE APPROX. deg. F (deg. C)																	4
													42							80
	AT 50% RH
A	73 (23)									AIR										(27)
												40
B	70 (21)																										(%)
C	67 (19)									DRY	8														HUMIDITY
D	63 (17)							POUND		3
									36
																			75
							PER											(24)
								4
								3
				BTU																				RELATIVE
							32
																70
					30
														(21)
			28
															0
	ENTHALPY												1	0			0
		26										65				9		80
	4											(18)							70
	2																				0
	2																			6
	2									60											50
	0									(16)
	2										A											4	0
8								55
1								(13)		B														30
6
1							50
4								C
						(10)
1																										20
2			45				D
1			(7)
		40
																													0
		(4)
																													1
	35
	(2)
																			D C		B	A
																													HIGH LIMIT
																													CURVE
	35	40	45				50	55		60		65				70			75		80	85		90	95	100		105	110
	(2)	(4)	(7)				(10)	(13)		(16)		(18)				(21)			(24)		(27)	(29)		(32)	(35)	(38)		(41)	(43)
	APPROXIMATE DRY BULB TEMPERATURE--degrees F (degrees C)

C06037

Fig. 43 ---Enthalpy Changeover Set Points

Demand Controlled Ventilation (DCV)						OA	) + (TR x	RA
When using the	EconoMi$er	IV	for demand	controlled	(T				) =T
						100		100
ventilation, there are some equipment selection criteria which					O x				M
should be considered. When selecting the heat capacity and cool					TO = Outdoor-Air Temperature
capacity of the equipment, the maximum ventilation rate must be
evaluated for design conditions. The maximum damper position					OA = Percent of Outdoor Air
must be calculated to provide the desired fresh air.					TR = Return-Air Temperature
Typically the maximum ventilation rate will be about 5 to 10%					RA = Percent of Return Air
					TM = Mixed-Air Temperature
more than the typical cfm required per person, using normal
outside air design criteria.					Once base ventilation has been determined, set the minimum
A proportional anticipatory strategy should be taken with the					damper position potentiometer to the correct position.
					The same equation can be used to determine the occupied or
following conditions: a zone with a large area, varied occupancy,
and equipment that cannot exceed the required ventilation rate at					maximum ventilation rate to the building. For example, an output
design conditions. Exceeding the required ventilation rate means					of 3.6 volts to the actuator provides a base ventilation rate of 5%
the equipment can condition air at a maximum ventilation rate					and an output of 6.7 volts provides the maximum ventilation rate
that is greater than the required ventilation rate for maximum					of 20% (or base plus 15 cfm per person). Use Fig. 42 to
occupancy. A proportional-anticipatory strategy will cause the					determine the maximum setting of the CO2 sensor. For example,
fresh air supplied to increase as the room CO2 level increases					a 1100 ppm set point relates to a 15 cfm per person design. Use
even though the CO2 set point has not been reached. By the time					the 1100 ppm curve on Fig. 45 to find the point when the CO2
the CO2 level reaches the set point, the damper will be at					sensor output will be 6.7 volts. Line up the point on the graph
maximum ventilation and should maintain the set point.					with the left side of the chart to determine that the range
In order to have the CO2 sensor control the economizer damper in					configuration for the CO2 sensor should be 1800 ppm. The
this manner, first determine the damper voltage output for					EconoMi$er IV controller will output the 6.7 volts from the CO2
minimum or base ventilation. Base ventilation is the ventilation					sensor to the actuator when the CO2 concentration in the space is
required to remove contaminants during unoccupied periods. The					at 1100 ppm. The DCV set point may be left at 2 volts since the
					CO2 sensor voltage will be ignored by the EconoMi$er IV
following equation	may be used	to	determine the	percent of
outside-air entering the building for a given damper position. For					controller until it rises above the 3.6 volt setting of the minimum
					position potentiometer.
best results there should be at least a 10 degree difference in
					Once the fully occupied damper position has been determined, set
outside and return-air temperatures.

the maximum damper demand control ventilation potentiometer to this position. Do not set to the maximum position as this can result in over-ventilation to the space and potential high-humidity levels.

40