Watlow DIN-A-MITE Style B - Manual (Page 9)

WATLOW DIN-A-MITE Style B User's Manual
9
NOTE: The current transformer must be in the center uncontrolled leg on a 2-leg DIN-A-MITE.
Non-latching Alarm Option
(models DB_ _ -
_ _ _ _ - S _ _ _ )
Shorted SCR (silicon-controlled rectifier) Alarm
Non-latching Operation
The shorted SCR detector compares the input
command signal and actual load current. If load
current is present without an input signal then the
shorted SCR alarm will energize the alarm triac
output. This is a non-latching alarm. This output can
be used to drive various indication devices, such as a
coil, light, buzzer, etc. See the alternative latching
circuit section below.
V Å
13 14
Triac
RY1
Coil
Reset Switch
RY1A
L1
L2
RY1B
Normally open
Common
Normally closed (External alarm relay
contacts, set A)
(External alarm relay
contacts, set B)
Latching Alarm Relay Circuit
Ungrounded Delta or Wye Load 3-phase, 2-leg DIN-A-MITE
Current
Transformer (CT)
Delta
Load
Ungrounded
Wye Load
6
5 4
V~
(ac)
120 or 240V~ (ac)
@ 300mA maximum
energizes on alarm
Semiconductor
Fuses
Signal
Alarm Relay
or Indicator
1A
7
8
9
10
11
12
13
14
15
16
1 2 3
4 5 6
High-limit
Contactor (CR1)
CT
DB20-60C0-S000
NOTE:
Use a grounding conductor
terminal plate (fork
terminal) having upturned
lugs or the equivalent to
hold the wire in position.
Maximum 6 mm
2 (10 AWG)
wire.