Toshiba RC820 - Manual (Page 7)

WIRING
Low-vo(tage power supply
600 V AC or less
-Sh
Low-voltage
Contractor
I Ì I a I 3 I 4 15 [ 5 I 7 f
2E Relay
^Stop
Start
Higti-voltaga power supply PT w control transformer
2.AKV—13.8K\/ AC /[100~t20V Sacondaiy)
iJ\Operatìng
Xoil
L/
Control
Tsrminal
Numbers
High
voltage
CT
(Notes)
I WOTOn
"Connections of control power source
AC 100-120V—Terminals 1-2
AC 200-240V—Terminals 1-3
For other voit., use CPT.
"‘Connections of output contacts
NC“Oontact {opened when the 2E
Relay operated)—Terminals 8-9
NO-contact (closed when the 2E
Relay operated)—Terminals 9-10
“‘Connections of Remote reset switch
LOW-VOLTAGE
|_High-vortag©__
^ contactor
i|i
^ stop
^ Start
15 Operating
' Coll
l|2[3М4|5М6|7|a|9|To
I 2 £ Relay
b a
o
P\
Hlgh“V 0ita9& CT sscondar/ circuit
wires pass through the windows of
the built-in CT's,
HIGH-VOLTAGE
HOW TO SET
Selection of the suitable model may require some preli­
minary calculations. See “Current Setting” to determine
if the calculated “Current Setting %” can be obtained
with the selected model given the motor full load current
(FLA). Model Selection can also be influenced by wire
size which limits the number of turns that can be passed
through the CT windows.
(1) Current Setting
(2E AT Rating)X(External CT Ratio)
N{g-i------------------------- ----------------------------
N(T) = Number of wire turns through 2E built-in CTs,
round off to nearest integer.
/m . 0 4 *- FLAxNxIOO
® "^9 0 ) ^ 2 ^ yjj p 3 (jpg| ^ (External CT Ratio)
Notes: * Select the external CT ratio so that the current
setting % is as close to 100% as possible.
If no external CT are used, substitute with
“
1
.
0
” .
**For 1.15 Service Factor Motors. If the motor
has a 1.0 S.F. multiply the calculated “Current
Setting %” by 0,93, (Practice in USA)
Example: 200HP, 460V, 240A Full Load. 1.15 S.F.
Across-the-line start.
240 Amps exceeds the highest rated 2E
Relay, therefore, external CT’s must be
used, and the HPIY, 7 AT rated 2E, will be
chosen as the standard model when the
current exceeds the HP3Y’s rating. If 300/5
CT’s are used,
41, m 4 0,4- n/ 240xNfT)x100%
the Current Setting % =---------------------------
7x(M0)
5 "'
= N01x57.14%.
And if 2 turns through the 2E Relay’s CT
windows (from the external CT’s) are used,
the % Dial
Setting = 2x57.14=114% = 110% or 115%
(2) Time setting
Determine the protection curve from 2E Relay
operating curves, and read the operating time at 600%
of setting current. Adjust the time setting dip switch
to the nearest setting above the operating time.