ELECTRICAL CONNECTIONS
(A)
ELECTRICAL CONNECTIONS
TECNO 28-L and 38-L
(B)
ELECTRICAL CONNECTIONS
TECNO 50-L
(C)
TECNO 50-L CALIBRATION OF THEREMAL RELAY
(D)
D867
ELECTRICAL CONNECTIONS (A)
set up by the installer
Use flexible cables according to regulation EN 60
335-1:
• if in PVC boot, use at least H05 VV-F
• if in rubber boot, use at least H05 RR-F.
All the cables to be connected to the burner
sockets 5)(A) must be routed through the fair-
leads, supplied by the manufacturer for insertion
into the holes in the plate, preferably those on the
left side, after having removed the thin dia-
phragm effectively closing the aperture, as al-
ready explained above.
1 - Pg 11 Three-phase power supply
2 - Pg 11 Single-phase power supply
3 - Pg 9
4 - Pg 9
5 - Plug/Socket
LAYOUT (B)
The TECNO 28-L and 38-L models electrical
connection single-phase 230V power supply
D3277
Cable section not indicated: 1,5 mm
LAYOUT (C)
The TECNO 50-L models electrical connec-
tion three-phase 230/400 V power supply
with neutral phase wire
Cable section not indicated: 1,5 mm
Key to wiring layouts (B) - (C)
h1 - 1st stage hourcounter
h2 - 2nd stage hourcounter
IN - Manual burner stop switch
X4 - 4 pole plug
X5 - 5 pole plug
X7 - 7 pole plug
S
- Remote lock-out signal
TL - Limit control device system:
TR - High-low mode control device system:
TS - Safety control device system:
D3232
Important: the burner is factory set for two-
stage operation and it must therefore be con-
nected to the TR remove control device to com-
mand light oil valve V2.
Alternatively, if single stage operation is
required, instead of control device TR install a
jumper lead between terminals T6 and T8 of
connector X4.
LAYOUT (D)
Calibration of thermal cut-out 17)(A)p.3
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 cur-
sor 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.
NOTES
• Burner TECNO 50-L leaves 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-
D3228
out as well.
• The TECNO 28-L, 38-L and 50-L burners have
been type-approved for intermittent operation.
This means they should compulsorily be stopped
at least once every 24 houres to enable the con-
trol box to perform checks of its own efficiency at
start-up. Burner halts are normally provided for
automatically by the boiler load control system.
WARNING:
Do not invert the neutral with the phase
wire in the electricity supply line.
9
Control device TL
Control device TR
This shuts down the burner when the boiler
temperature or pressure exceeds the set-
point value.
This controls operating stages 1 and 2 and
is necessary only for two-stage operation.
This operates when TL is faulty.
2
2