Begin Start-Up; Figure 13: Automatic Burner Control Sequence - Addison UHA 150 Installation, Operation & Service Manual

UHA S U H
TANDARD NIT EATER

11.2 Begin Start-Up

11.2.1 Before Operating the Heater
To ensure that all the controls are in safe working
order, operate the heater for the first time with the
isolating gas valve turned off and power supply
turned on.
1. Turn off the isolating gas valve.
2. Turn up the thermostat above room
temperature. The automatic ignition
sequence will now begin as described
on Page 28, Figure 13.
There will be no ignition of the burner and lockout
will occur, which proves the controls are operating
correctly.

Figure 13: Automatic Burner Control Sequence

Burner Sequence for Ignition Control
START
Thermostat 24 V
Flue Blower
NO
P
Pressure
Switch
C
NC
Ignition Spark
Start Gas Valve
Flame Signal
Axial Fan
*Purge time begins at pressure switch change over.
Required Incoming Signals
Signals Output By Control
28 of 49
I O
NSTALLATION PERATION AND
30 Seconds Purge*
30 Seconds Delay
S M
ERVICE ANUAL
ts = 10 Seconds
If at any stage the flame fails, the control will retry
for ignition. The control has four trials for ignition
before a one hour lockout.
RUN
SHUT DOWN
30 Seconds Post Purge
90 Seconds Delay