Lincoln Electric X-TRACTOR 3A Service Manual page 13

X-TRACTOR ® 3A
TERMINAL
STRIP
MOTOR CONTROL CIRCUITRY
24 VAC is applied to several components. 24 VAC is applied to the
on/off switch (S2), timer (T1), timer (T2), cleaning switch and to a set
of auxiliary contacts located on motor relay (K1). When the on/off
switch (S2) is turned on, 24 VAC is applied to the auto/manual switch
and the N.O. contacts on timer (T2).
When the auto/manual switch is closed or timer (T2) is activated
from an external closure at the remote receptacle, 24 VAC is applied
through a set of auxiliary contacts (F1) to motor relay (K1). The motor
relay (K1) is then energized and three phase power is applied to fan
motor (M1).
Figure E.3 - Motor control circuitry
3 PHASE 3 PHASE
F1
T1
TIMER
K1
AUXILIARY
ACTIVATION
CONTACTS
SIGNAL
N.O.
24VAC
460V
CONTROL
TRANSFORMER
NOTE: Unshaded areas of Block Logic
Diagram are the subject of discussion
E-3
K1 MOTOR
RELAY
M1
FAN
MOTOR
3Φ
CLEANING
SWITCH
T1 TIMER
CONTACTS
N.O.
T2 CONTACTS
S2
24VAC
ON/OFF
SWITCH
T2
TIMER
ACTIVATION
SIGNAL
THEORY OF OPERATION
CLEANING
DIGITAL
SOLENOID
TIMER
VALVE
N.O.
F1 AUXILIARY
CONTACTS
AUTO/MANUAL
SWITCH
PINS
1 + 2
REMOTE
RECEPTACLE