Carrier WeatherMaster Puron 48HC D17 Service And Maintenance Instructions page 53

minimum or base ventilation. Base ventilation is the ventila-
tion required to remove contaminants during unoccupied peri-
ods. The following equation may be used to determine the per-
cent of outside air entering the building for a given damper po-
sition. For best results, there should be at least a 10 degree
difference in outside-air and return-air temperatures.
OA
(T x ) + (T
O
100
T = Outdoor-Air Temperature
O
OA = Percent of Outdoor Air
T = Return-Air Temperature
R
RA = Percent of Return Air
T = Mixed-Air Temperature
M
Once base ventilation has been determined, set the minimum
damper position potentiometer to the correct position.
The same equation can be used to determine the occupied or
maximum ventilation rate to the building. For example, an out-
put of 3.6 volts to the actuator provides a base ventilation rate
of 5% and an output of 6.7 volts provides the maximum venti-
lation rate of 20% (or base plus 15 cfm per person). Use Fig. 69
to determine the maximum setting of the CO
ample, an 1100 ppm setpoint relates to a 15 cfm per person de-
sign. Use the 1100 ppm curve on Fig. 69 to find the point when
the CO sensor output will be 6.7 volts. Line up the point on
2
the graph with the left side of the chart to determine that the
range configuration for the CO
The EconoMi$er IV controller will output the 6.7 volts from
the CO sensor to the actuator when the CO
2
the space is at 1100 ppm. The DCV setpoint may be left at
2 volts since the CO sensor voltage will be ignored by the
2
EconoMi$er IV controller until it rises above the 3.6 volt set-
ting of the minimum position potentiometer.
Once the fully occupied damper position has been determined,
set the maximum damper demand control ventilation potenti-
ometer 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.
CO SENSOR CONFIGURATION
2
The CO sensor has preset standard voltage settings that can be
2
selected anytime after the sensor is powered up. See Table 21.
Use setting 1 or 2 for Carrier equipment. See Table 21.
1. Press Clear and Mode buttons. Hold at least 5 seconds
until the sensor enters the Edit mode.
2. Press Mode twice. The STDSET Menu will appear.
3. Use the Up/Down button to select the preset number. (See
Table 21.)
4. Press Enter to lock in the selection.
5. Press Mode to exit and resume normal operation.
RA
x ) = T
R M
100
sensor. For ex-
2
sensor should be 1800 ppm.
2
concentration in
2
Table 21 — EconoMi$er IV Sensor Usage
ECONOMI$ER IV WITH OUTDOOR-AIR
APPLICATION
Outdoor Air
Dry Bulb
Differential
Dry Bulb
Single Enthalpy
Differential Enthalpy
CO for DCV
2
Control using a
Wall-Mounted
CO Sensor
2
CO for DCV
2
Control using a 33ZCSENCO2† and
Duct-Mounted 33ZCASPCO2**
CO Sensor
2
* CRENTDIF004A00 and CRTEMPSN002A00 accessories are used on
many different base units. As such, these kits may contain parts that will
not be needed for installation.
† 33ZCSENCO2 is an accessory CO
** 33ZCASPCO2 is an accessory aspirator box required for duct-
mounted applications.
†† CRCBDIOX005A00 is an accessory that contains both 33ZCSEN-
CO2 and 33ZCASPCO2 accessories.
The custom settings of the CO
after the sensor is energized. Follow the steps below to change
the non-standard settings:
1. Press Clear and Mode buttons. Hold at least 5 seconds
until the sensor enters the Edit mode.
2. Press Mode twice. The STDSET Menu will appear.
3. Use the Up/Down button to toggle to the NONSTD menu
and press Enter.
4. Use the Up/Down button to toggle through each of the
nine variables, starting with Altitude, until the desired set-
ting is reached.
5. Press Mode to move through the variables.
6. Press Enter to lock in the selection, then press Mode to
continue to the next variable.
DEHUMIDIFICATION OF FRESH AIR WITH DCV
(DEMAND CONTROLLED VENTILATION) CONTROL
If normal rooftop heating and cooling operation is not adequate
for the outdoor humidity level, an energy recovery unit and/or
a dehumidification option should be considered.
ECONOMI$ER IV PREPARATION
This procedure is used to prepare the EconoMi$er IV for trou-
bleshooting. No troubleshooting or testing is done by perform-
ing the following procedure.
NOTE: This procedure requires a 9-v battery, 1.2 kilo-ohm resis-
tor, and a 5.6 kilo-ohm resistor, which are not supplied with the
EconoMi$er IV.
IMPORTANT: Be sure to record the positions of all poten-
tiometers before starting troubleshooting.
1. Disconnect power at TR and TR1. All LEDs should be off.
Exhaust fan contacts should be open.
2. Disconnect device at P and P1.
3. Jumper P to P1.
4. Disconnect wires at T and T1. Place 5.6 kilo-ohm resistor
across T and T1.
5. Jumper TR to 1.
6. Jumper TR to N.
53
DRY BULB SENSOR
Accessories Required
None. The outdoor air dry bulb sensor
is factory installed.
CRTEMPSN002A00*
HH57AC078
HH57AC078 and CRENTDIF004A00*
33ZCSENCO2
OR CRCBDIOX005A00††
sensor.
2
sensor can be changed anytime
2