Bryant DURAPAC PLUS SERIES 542J - Manual (Page 31)

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E. DCV Minimum and Maximum Position
To check the DCV minimum and maximum position:
1. Make sure EconoMi$erIV preparation procedure has
been performed.
2. Connect a 9-v battery to AQ (positive node) and AQ1
(negative node). The DCV LED should turn on. The
actuator should drive to between 90 and 95% open.
3. Turn the DCV Maximum Position potentiometer to
midpoint. The actuator should drive to between 20
and 80% open.
4. Turn the DCV Maximum Position potentiometer to
fully CCW. The actuator should drive fully closed.
5. Turn the Minimum Position potentiometer to mid-
point. The actuator should drive to between 20 and
80% open.
6. Turn the Minimum Position Potentiometer fully CW.
The actuator should drive fully open.
7. Remove the jumper from TR and N. The actuator
should drive fully closed.
8. Return EconoMi$erIV settings and wiring to normal
after completing troubleshooting.
F. Supply-Air Input
To check supply-air input:
1. Make sure EconoMi$erIV preparation procedure has
been performed.
2. Set the Enthalpy potentiometer to A. The Free Cool
LED turns on. The actuator should drive to between
20 and 80% open.
3. Remove the 5.6 kilo-ohm resistor and jumper T to T1.
The actuator should drive fully open.
4. Remove the jumper across T and T1. The actuator
should drive fully closed.
5. Return EconoMi$erIV settings and wiring to normal
after completing troubleshooting.
G. EconoMi$erIV Troubleshooting Completion
This procedure is used to return the EconoMi$erIV to opera-
tion. No troubleshooting or testing is done by performing the
following procedure.
1. Disconnect power at TR and TR1.
2. Set enthalpy potentiometer to previous setting.
3. Set DCV maximum position potentiometer to previ-
ous setting.
4. Set minimum position, DCV set point, and exhaust
potentiometers to previous settings.
5. Remove 620-ohm resistor from terminals S
R
and +.
6. Remove 1.2 kilo-ohm checkout resistor from terminals
S
O
and +. If used, reconnect sensor from terminals S
O
and +.
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. Recon-
nect wires at T and T1.
10. Remove jumper from P to P1. Reconnect device at P
and P1.
11. Apply power (24 vac) to terminals TR and TR1.
Table 15 — Check Valve Functions
CHECK VALVE
IDENTIFICATION
(See Fig. 42 and 43)
LOCATION
COOLING
CYCLE
HEATING
CYCLE
COOLING CYCLE
CHECK VALVE STUCK
HEATING CYCLE
CHECK VALVE STUCK
Open Closed Open Closed
A
Outdoor coil;
Header
Closed Open
Lose circuiting in
outdoor coil. Acts
like low charge.
Normal Normal
Bottom 3 circuits
restricted
B
Outdoor coil;
Liquid line feeding
fixed orifice
Open Closed Normal
Lose some
capacity Restricted outdoor
fixed orifice
Normal
C
Outdoor coil;
Liquid line leaving
coil
Closed Open
Restricted
liquid line
Normal Normal
Flooding outdoor
coil and compressor
D
Indoor coil; Liquid
line feeding fixed
orifice
Open Closed Normal
Restricted
indoor
fixed orifice
Lose some capacity Normal
E
Indoor coil; Liquid
line leaving coil
Closed Open
Bypasses coil and
floods compressor
Normal Normal
Restricted
liquid line
F
Indoor coil;
Header
Open Closed Normal
Bottom circuits
of indoor coil
inactive Lose indoor coil
circuiting — symptom
of low charge
Normal