Riello RS 70 Instrucciones De Instalación, Funcionamiento Y Mantenimiento página 13

CALIBRATION OF THERMAL RELAY
(A)
LAYOUT (A)
Calibration of thermal cut-out 7)(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, 380V, the cursor
should be positioned to "MIN".
• If the motor is delta-powered, 220V, the cur-
sor should be positioned to "MAX".
Even if the scale of the thermal cut-out does not
include rated motor absorption at 380V, protec-
tion is still ensured in any case.
20083350
N.B.
• The burners leave the factory preset for 380V
power supply. If 220V power supply is used,
change the motor connection from star to
delta and change the setting of the thermal
cut-out as well.
• The supply to the auxiliary circuits must be
220-230 V.
• The burners have been type-approved 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 burners are factory set for two-stage
operation and must therefore be connected to
control device TR.
Alternatively, if single stage operation is
required, instead of control device TR install a
jumper lead between terminals 6 and 7 of the
terminal strip.
WARNING:
Do not invert the neutral with the phase
wire in the electricity supply line. Invert-
ing the wires will make the burner go into
lock-out because of firing failure.
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