12
LAYOUT (A) - The GAS 9/2 Models electrical
connection three-phase power supply with-
out leak detection control device.
LAYOUT (B) - The GAS 9/2 Models electrical
connection three-phase power supply with
VPS leak detection control device.
Gas valve 8)-9)p. 10 leak detection control takes
place immediately before every burner starting.
KEY TO LAYOUTS
(A) - (B)
IN
- Manual burner stop switch
MB
- Burner terminal strip
PG
- Min. gas pressure switch
H
- Remote lock-out signal
H1
- Remote lock-out signal of leak detection
control device
TR
- High-low mode load control system:
controls operating stages 1 and 2.
If the burner is to be set up for single
stage operation, replace of remote con-
trol device TR with a jumper.
TL
- Load limit remote control system:
shuts down the burner when the boiler
temperature or pressure reaches the pre-
set value.
TS
- Safety load control system:
operates when TL is faulty
VR1 - Gas valve, stage 1
VR2 - Gas valve, stage 2
VS
- Safety valve
XP
- Plug for leak detection control device
LAYOUT (C)
Calibration of thermal cut-out 7)(A) p. 5
This is required to avoid motor burn-out in the
event of a significant increase in power absorp-
tion caused by a missing phase.
- If the motor is star-powered,
400 V
, the cursor
should be positioned to "MIN".
- If the motor is delta-powered,
230 V
, the cursor
should be positioned to "MAX".
Even if the scale of the thermal cut-out does not
include rated motor absorption at 400 V, protec-
tion is still ensured in any case.
N.B.
• Models GAS 9/2 three-phase leave the factory
preset for 400 V power supply. If 230 V power
supply is used, change the motor connection
from star to delta and change the setting of the
thermal cut-out as well.
• The GAS 9/2 burners have been type- ap-
proved for intermittent operation. This means
they should compulsorily be stopped at least
once every 24 hours to enable the control box
to check its own efficiency at start-up. Burner
halts are normally provided for automatically by
the boiler load control system.
If this is not the case, a time switch should be
fitted in series to IN to provide for burner shut-
down at least once every 24 hours.
• The GAS 9/2 burner is factory set for two-stage
operation and must therefore be connected to
control device TR.
Alternatively, if single stage operation is re-
quired, instead of control device TR install a
jumper lead between terminals 6 and 7 of the
terminal strip.
Do not invert the neutral with
the phase wire in the electric-
ity supply line. Inverting the
wires will make the burner go
into lock-out because of fir-
ing failure.
CALIBRATION OF THERMAL RELAY
(A)
(B)
ELECTRICAL CONNECTION OF BURNER BY INSTALLER
Without leak detection control device
ELECTRICAL CONNECTION OF BURNER BY INSTALLER
With VPS leak detection control device
Cable selection
GAS 9/2
230V
400V
F
S
A
mm
2
T 50
6
T 40
4
D2901
D2903
D867
(C)
DANGER
Summary of Contents for GAS 9/2
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