Carrier 48TJ016-028 - Manual (Page 48)

TROUBLESHOOTING
Unit Troubleshooting — Refer to Tables 27 29 and
Fig. 60.
EconoMi$erlV Troubleshooting — See Table 30
for EconoMiSerlV logic.
A functional view of the EconoMi$erIV is shown in Fig. 61.
Typictil settings, sensor ranges, and jumper positions are also
shown. An EconoMi$erIV simulator program is available from
CiU'rier to help with EconoMi$erIV training and troubleshooting.
ECONOMI$ERIV PREPARATION---This procedure is
used to prepare the EconoMi$erIV for troubleshooting. No
troubleshooting or testing is done by performing the following
procedure.
NOTE: This procedure requires a 9-v batteiy, 1.2 kilo-ohm
resistor, and a .5.6 kilo-ohm resistor which are not supplied
with the EconoMi$erIV.
IMPORTANT: Be sure to record tire positions of all poten­
tiometers before starting troubleshooting.
1. Disconnect power at TR and TRl. All LEDs should be
off. Exhaust fan contacts should be open.
2. Disconnect device at P and PI.
3. JumperP to PI.
4. Disconnect wires at T and T1. Place .5.6 kilo-ohm resistor
across T and T1.
5. Jumper TR to 1.
6. Jumper TR to N.
7. If connected, remove sensor from terminals So and -i-.
Connect 1.2 kilo-ohm 4074EJM checkout resistor across
terminals So and
-I-.
8. Put 620-ohm resistor across terminals S r and -i-.
9. Set minimum position, DCV set point, and exhaust
potentiometers fully CCW (counterclockwise).
10. Set DCV maximum position potentiometer fully CW
(clockwise).
11. Set entlialpy potentiometer to D.
12. Apply power (24 vac) to terminals TR and TRl.
DIFFERENTIAL ENTHALPY — To check differential
enthalpy:
1. Make sure EconoMl$erIV piepaation procedure has
been performed.
2. Place 620-ohm resistor across So and -i-.
3. Place 1.2 kilo-ohm resistor across S
r and -i-. The Free
Cool LED should be lit.
4. Remove 620-ohm resistor across So and -I-. The Free
Cool LED should turn off.
5. Return EconoMi$erJV settings and wiring to normiil
after completing troubleshooting.
SINGLE ENTHALPY — To check single enthalpy:
1. Make sure EconoMi$erIV prepiu'ation procedure has
been performed.
2. Set the enthalpy potentiometer to A (fully CCW). The
Free Cool LED should be lit.
3. Set the enthiilpy potentiometer to D (fully CW). The Free
Cool LED should turn off.
4. Return EconoMi$erIV settings and wiring to normal
after completing troubleshooting.
DCV (Demand Controlled Ventilation) AND POWER
EXHAUST-- To check DCV and Power Exhaust:
1. Make sure EconoMi$erIV prepai'ation procedure has
been performed.
2. Ensure terminals AQ and AQl ae open. The LED for
both DCV and Exhaust should be off Tire actuator
should be fully closed.
3. Connect a 9-v batteiy to AQ (positive node) and AQl
(negative node). Tire LED for both DCV and Exhaust
should turn on. The actuator should diive to between 90
and 95% open.
4. Turn tlie Exhaust potentiometer CW until tire Exhaust
LED turns off. The LED should turn off when the
potentiometer is approximately 90%. The actuator should
remain in position.
5. Turn the DCV set point potentiometer CW until the DCV
LED turns off. The DCV LED should turn off when the
potentiometer is approximately 9-v. The actuator should
drive fully closed.
6. Turn the DCV and Exhaust potentiometers CCW until
the Exhaust LED turns on. The exhaust contacts will
close 30 to 120 seconds after the Exhaust LED turns on.
7. Return EconoMi$erIV settings and wiring to normal
after completing troubleshooting.
DCV MINIMUM AND MAXIMUM POSITION — To check
the DCV minimum and maximum position:
1. Make sure EconoMi$erIV preparation procedure has
been peifonned.
2. Connect a 9-v batteiy to AQ (positive node) and AQl
(negative node). The DCV LED should turn on. Tire
actuator should diive to between 90 and 95% open.
3. Turn the DCV Maximum Position potentiometer to mid­
point. Tire actuator should drive to between 20 and 80%
open.
4. Turn the DCV Maximum Position potentiometer to lltlly
CCW. Tire actuator should drive fully closed.
5. Turn the Minimum Position potentiometer to midpoint.
The actuator should diive to between 20 and 80% open.
6. Turn the Minimum Position Potentiometer folly CW. The
actuator should drive fully open.
7. Remove tlie jumper from TR and N. The actuator should
drive fully closed.
8. Return EconoMi$erIV settings and wiring to nonntil
after completing troubleshooting.
SUPPLY-AIR INPUT — To check supply-air input:
1. Make sure EconoMi$erIV preparation procedure has
been peifonned.
2. Set the Entlialpy potentiometer to A. The Free Cool LED
turns on. The actuator should drive to between 20 and
80% open.
3. Remove the 5.6 kilo-ohm resistor and jumper T to T1.
The actuator should diive folly open.
4. Remove tlie jumper across T and T1. The actuator should
drive fully closed.
5. Return EconoMi$erIV settings and wiring to normal
after completing troubleshooting.
ECONOMISER IV TROUBLESHOOTING COMPLE­
TION — This procedure is used to return the EconoMi$erIV
to operation. No troubleshooting or testing is done by perform­
ing the following procedure.
1. Di sconnect power at TR and TR 1.
2. Set enthalpy potentiometer to previous setting.
3. Set DCV maximum position potentiometer to previous
setting.
4. Set minimum position, DCV set point, and exhaust
potentiometers to previous settings.
5. Remove 620-ohm resistor from terminals S r and -i-.
6. Remove 1.2 kilo-ohm checkout resistor from terminals So
and -I-. If used, reconnect sensor from tenninals So and -I-.
7. Remove jumper from TR to N.
8. Remove jumper from TR to 1.
9. Remove 5.6 kilo-ohm resistor from T and T1. Reconnect
wires at T and T1.
10. Remove jumper from P to PI. Reconnect device at P and
PI.
11. Apply power (24 vac) to terminttls TR and TRl.
48