46
4.2 ELECTRICAL CONNECTION TO THE TERMINAL STRIP
(installer-set)
LAYOUT (A) - Electrical connection P 140-200-300 T/G
burners with direct motor starting
Cables cross-section
LAYOUT (B) - Electrical connection P 300-450 T/G burners
with star-delta motor starting
Cables cross-section
KEY TO LAYOUTS (A) - (B)
I1 -
Burner manual stop switch
MA -
Star-delta starter terminal strip
MB -
Burner terminal strip
PS -
Reset push-button
S
-
Remote lock-out signal
TL -
Load limit remote control system:
shut down the burner when the boiler
temperature or pressure reaches the
maximum preset value
TS -
Safety load control system:
operateds when TL is faulty
T2 -
2
nd
stage load control system
T3 -
3
rd
stage load control system
SCHEMA (C) - Calibration of thermal relay
This is required to avoid motor burn-out in the
event of a significant increase in power
absorption caused by a missing phase.
• If the motor is star-powered, 400 V, the cursor
should be positioned to “MIN”.
• If it is delta-powered, 230 V, the cursor should
be positioned to “MAX”.
If the scale of the thermal relay does not include
rated motor absorption at 400 V, protection is
still ensured.
P 140 T/G
P 200 T/G
P 300 T/G
230 V
400 V
230 V
400 V
230 V
400 V
F
A
25
25
35
25
63
50
L
mm
2
2,5
2,5
4
2,5
6
4
P 300 T/G
P 450 T/G
230 V
400 V
230 V
400 V
F
A
50
35
63
50
L
mm
2
6
4
10
6
E
mm
2
4
2,5
6
4
P 140 - 200 - 300 T/G
DIRECT MOTOR STARTING
D2568
(C)
THERMAL RELAY
(B)
P 300 - 450 T/G
STAR-DELTA MOTOR STARTING
(A)
Check the lock-out by darkening the
photo-cell after removal of the cover.
ATTENTION: HIGH VOLTAGE
NOTE:
D2570
