Reznor LDAP Unit Installation Manual - Manual (Page 23)

Form I-LDAP, P/N 207733R6, Page 23
Operating Sequence (all sizes)
1 . Set thermostat at lowest setting (fan switch at
“AUTO” position).
2. Turn on the manual gas valve(s).
3. Turn on power to the heater.
4. Set thermostat at desired setting.
5. Thermostat calls for heat, energizing the venter
motor(s).
6. Main combustion air pressure switch (Sizes 800 and
1200) and heat section pressure switch(es) close,
firing heat section(s) (Unit fires at low fire when using
two-stage thermostat).
7. Burner flame is sensed, and in 30 seconds the fan
motor(s) is energized.
8. High stage of thermostat calls for heat, firing all heat
sections at full rate (on two-stage units).
9. Set fan switch at “ON” position for continuous fan
operation.
10. If the flame is extinguished during main burner
operation, the integrated control system closes the
main valve of that heat section and must be reset by
interrupting power to the control circuit (see lighting
instructions).
NOTES (apply to FIGURES 17, 18, and 19)
1. The following controls are field-installed options:
Thermostat
2. Dotted wiring installed by others.
3. CAUTION: If any of the original wiring as supplied
with the appliance must be replaced, it must be
replaced with wiring material having a temperature
rating of at least 105°C, except for sensor lead wire
and limit wiring which must be 150°C.
4. Use 18 gauge wire for all wiring on the heater.
5. Line and fan motor branch wire sizes should be of a
size to prevent voltage drops beyond 5% of supply
line voltage.
6. Size 400, see thermostat wiring diagram in FIGURE
14, page 21. Size 800, see thermostat wiring diagram
in FIGURE 15, page 21. Size 1200, see thermostat
wiring diagram in FIGURE 16, page 22.
7. The control transformer has a dual voltage primary.
For 230V heaters, the black lead goes to the “240”
terminal. Cap the “208” terminal.
For 208V heaters, the black lead goes to the 208”
terminal. Cap the “240” terminal.
8. When providing or replacing fuses in the fusible
disconnect switch, use dual elements time delay fuses
and size according to 1.25 times the maximum total
input amps.
9. The line side of the lockable disconnect switch must
be connected to the incoming power supply such that
the voltage between Terminal L1 and Ground is the
greater value.
7.4 Wiring Diagrams
CAUTION: If any of the original wire as supplied with the appliance must be replaced, it
must be replaced with wiring material having a temperature rating of at least 105°C, except
for limit control, high limit control, and sensor lead wires which must be 150°C. See Hazard
Levels, page 2.
7.3 Fan Motor(s)
• Size 400 has 1 fan motor.
• Size 800 has 2 fan motors.
• Size 1200 has 3 fan
motors.
Each heat section in the heater has a fan motor. Each fan motor(s) is equipped
with thermal overload protection of the automatic reset type. Should the
motor(s) refuse to run, it may be because of improper current characteristics.
Make certain that the correct voltage is available at the motor(s).
Fan Motor Wiring: White = Neutral
Black = High (Heat Speed)
Blue = Medium (Destratification Speed, Factory Wired)
Red = Low (Optional Destratification Speed, Field
Wired)
The main operating gas valve(s) is powered by the 24-volt control circuit
through the thermostat and safety controls. The gas valve is of the diaphragm
type providing regulated gas flow preset at the factory. (For location, see FIG-
URE 22, page 35.)
• Size 400 has 1 valve
• Size 800 has 2 valves
• Size 1200 has 3 valves.
Gas Valve(s)
FIGURE 17 - Model LDAP 400, page 24; FIGURE 18 - Model LDAP 800, page
25; and FIGURE 19 - Model LDAP 1200, page 26.are typical wiring diagrams.
The Operating Sequence and Notes below and the “Keys” on top of page 24,
apply to all three diagrams.