t>C8 ASSY-TRANSFER
SWITCH
CONTROL
CAUTIOH:
HIGH
Off
OFF VOLTAGE
30J
20
1
AETRANSFERD
1115
1
D STOPPING
BYPASS AiS2 BYPASS
li
4
9 7
<:>
K9
Wl
K6
I VOLTAGE
SENSOR
1t>GENERATOA
S1DE
§
PHASE
SENSOA
RELAY
.
rg:-;
:.ii SENSOR
30
•
~m-ET~~
$ENSOR
10
K8
§TRANSFER
RELAY
• TfME DELAY TRANSFER
AANGE: 0.3
lo
30
SECONDS
ON
ENERGfZAT~OH
NORM: 2
SECONDS
"TtME
DEL.AV STOPPING
AfTER
RETRANSFEA
RANGE 3
TO
300
SECONDS
ON
~NERGIZAllON
NOAU' 300SECONDS
K5
ON ON
K7
f
INST
ANT
TRANSFER
TOUNE
"TIME
OELAY
BETRANSFER
RANGE'
21'0
301lllNUT£S
ON
ENERGIZATION
NORM:
15MINUTES
K4
0
0
3 1
6 4
9 7
oP11
START
RE.LAY
.
nue
DELAY
STARTING
~:
0.1
to 10 SECONDS
NORM: 2 SECONDS
K3
C1
H--
FIGURE
2-4.
CONTROLLER
PCB
ASSEMBLY
NORMAL
OPERATION
During normal operation, the commercial power line is
connected to the Load terminals by the transfer switch
contacts
K1.
The
following
briefly
describes
the
required interaction
of
control components to close the
K1
contacts. Refer to Figure 2-S when reviewing this
information to gain an understanding of control
compo-
nent interaction. Then refer to wiring diagram specific to
your
transfer switch to identify where
your
transfer
switch may differ.
When commercial
power
is first applied, line voltage is
transformed to 120 volts AC and supplied to voltage
sensor relay
K6.
Energizing the coil of K6 will close its
normally open contacts to complete the circuit to relay
coils
K3,
K4,
KS,
and
K7.
Relay K7 energizes imme-
diately, and if the commercial (Normal) line contacts are
not
closed, the
K1
closing coil (CC) is energized. With
K1
closing coil energized, the normally open contacts of
K1
between Line and Load will close.
' 2-6
Once the transfer switch is closed to the normal line
side,
it
is held in that position and the closing coil is
de-energized
by
opening of the
K1
cutout switch
(CS).
The
cutout
switch
is
activated by the mechanical inter-
lock. Contact operation differs only in
how
they are held
in position, either electrically
or
mechanically.
Relay K6 can
be
either a voltage sensor with an adjusta-
ble
pickup
voltage,
or
a phase loss sensor, when the
voltage feeding the relay coil
drops
below
the relay
holding voltage.
During normal operation when K3 relay is energized, it
opens its normally closed contacts
of
the generator start
circuit, and prevents automatic starting of the generator
set
Relays K4 and
KS
(if equipped) function as described in
the Restoration
of
Commercial Power section.
To Next Page
Loading...