York D4IC-360 Technical Information Download Page 35

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17.3.- Low gas pressure (models D4IG)

If gas supply pressure falls below the gas pressure switch
(GS) set point, power supply to the ignition control circuit is
cut off, and this circuit becomes inoperative. The gas equip-
ment will reset automatically once the gas supply pressure
goes above the pressure switch set point, and the start-up
sequence will begin once again. See table 18.6 for gas valve
and thermal switch adjustments.

17.4.- Heating lock-out (electric heaters)

Should any of the electric heater phases not operate, check
heat protection devices F12 and F15 (105° C, manual re-
set heat switch). If F1 or F16 (77° C, automatic reset) fail
three times, the control board will detect this, turn off the
corresponding heater and display the failure on thermostat
DPC-1.
Also check short circuit and overload protection automatic
switches F21 and F22 (1

and 2

stages). The heat switches

and automatic switches can be accessed through the external
access panel of the electric heater.

17.5.- Motor overload protection

All motors of the hermetic compressors and fan motors are
protected against overloads by
means of an internal heat line cut-off switch. This protection
will reset automatically once the motor has cooled off suf-
ficiently. Externally, they are protected against short circuits
and overloads by means of automatic switches, curve K (DIN,
VDE 0660-104).
The indoor fan motor is protected by a motor-guard, adjusted
to the maximum amperage of the fan motor. In the case of
excessive power consumption in the three phases, the mo-
tor-guard opens, interrupting the electric power supply to the
Indoor Fan Contactor.
The motor-guard auxiliary contact opens and the control
board detects this, turns the entire unit off and displays the
failure on thermostat DPC-1.

18- Start-up of gas heating, models
D4IG

1. Check the type of gas to be used. Make sure it is the same

as shown on the identification plate located on the burner
assembly access door.

2. Make sure both the combustion air intake and the gas

discharge have no obstructions.

. Make sure the gas supply line is in compliance with safety

regulations and is prepared to supply adequate gas flow
and pressure. (See technical specifications in sections
4.1 and 18.8.)

Gas supply pipes to the unit must be air purged

18.2.- Turning on

This burner is equipped with automatic ignition systems.
Do not attempt to ignite it manually.

18.3.- Start-up, without the YKTOOL portable
test tool (accessory)

1.  Connect power supply to the unit.
2.  Open the gas supply tap to the unit.
.  Set the ambient thermostat to its maximum temperature

in heat.

4. The burner assembly will ignite. (It could take a few

minutes, depending upon the mode established on the
thermostat.)

18.4.- Start-up, with YKTOOL (accessory)

1.  Disconnect power supply to the unit.
2.  Set the Yktool on connector J9 of the Yklon board A1.
.  Connect power supply to the unit.
4.  Open the gas supply tap to the unit.
5.  On  the  main  menu,  select Test  heat  (No.  7).  Select

Auxiliary 1 and activate (ON). Repeat with Auxiliary 2,
and 4.

6. The 4 stages of the burner assembly will go on.

18.5.- Check list after start-up

After having activated the entire control circuit and the gas
heating is in operation, check the following:

1. Make sure there are no leaks in the unit and supply

pipes.

2. Check gas supply pressure with all gas units in the build-

ing operating at full capacity.

In no case should the pressure in the gas auxiliary line

above 25 mbar, nor the incoming pressure in the burner
assembly below 12.5 mbar.

. Make sure the gas pressures in the manifold are correct.

(See section 18.6 and Fig. 18.)