Input 1, 2, 3, 4 potentiometer, Input 1, 2, 3, 4 current transformer, Example: using a current transformer – Watlow EZ-ZONE RMC User Manual
Page 27
Warning:
ç
Use National Electric (NEC) or other
country-specific standard wiring and
safety practices when wiring and
connecting this controller to a power
source and to electrical sensors or pe-
ripheral devices. Failure to do so may
result in damage to equipment and
property, and/or injury or loss of life.
Note:
Maximum wire size termination and
torque rating:
• 0.0507 to 3.30 mm2 (30 to 12 AWG)
single-wire termination or two 1.31
mm2 (16 AWG)
• 0.8 Nm (7.0 in-lb.) torque
Note:
Adjacent terminals may be labeled
differently, depending on the model
number.
Note:
To prevent damage to the controller,
do not connect wires to unused ter-
minals.
Note:
Maintain electrical isolation between
digital input-outputs, switched dc/open
collector outputs and process outputs
to prevent ground loops.
Note:
If the last two digits of the part number
are "12", this equipment is suitable for
use in CLASS I, DIVISION 2, Groups A,
B, C and D or Non-Hazardous locations
only. Temperature Code T4
Warning:
ç
Explosion Hazard – Substitution of
component may impair suitability for
CLASS I, DIVISION 2.
Warning:
ç
Explosion Hazard - Do not disconnect
while the circuit is live or unless the
area is known to be free of ignitable
concentrations of flammable sub-
stances.
Watlow EZ-ZONE
®
RMC Module
•
24
•
Chapter 2 Install and Wire
Warning:
ç
Explosion Hazard - Dry contact closure
Digital Inputs shall not be used in Class
I Division 2 Hazardous Locations unless
switch used is approved for this ap-
plication .
Input 1, 2, 3, 4 Potentiometer
RMC Part # Digits 4, 6, 8, 10
S_
R_
Slot A, B, D, E
CW
CCW
• Use a 1 kΩ potentiometer.
Input 1: RMC(1,3,5)xxxxxxxxxxx (S1/R1)
Input 2: RMCxx(1,5)xxxxxxxxx (S2/R2)
Input 3: RMCxxxx(1,5)xxxxxxx (S3/R3)
Input 4: RMCxxxxxx(1,5)xxxxx (S4/R4)
Input 1, 2, 3, 4 Current Transformer
RMC Part # Digits 4, 6, 8, 10
T_
S_
Slot A, B, D, E
• Input range is 0 to 50 mA (ac).
• Current transformer part number: 16-0246
• 100 Ω input impedance
• Response time: 1 second maximum
• Accuracy +/-1 mA typical
Input 1: RMC(7)xxxxxxxxxxx (T1/S1)
Input 2: RMCxx(7)xxxxxxxxx (T2/S2)
Input 3: RMCxxxx(7)xxxxxxx (T3/S3)
Input 4: RMCxxxxxx(7)xxxxx (T4/S4)
Example: Using a Current Transformer
Controller
Output N
CT Input
L2
L1
Fuse
SSR
3A x 4
12A
48mA
48mA
12A x 4 = 48A
Turns around CT
Turns around CT
CT Primary Current
CT Secondary Current
Total current
CT Ratio R = 1000:1
:
I
s
= I
p
T/R = 50mA
CSC = I
p(full scale)
= 50mA(R)/T
CSI = Output N
I
s
= Current in secondary of current transformer
I
p
= Current in primary of current transformer
T = Number of turns through the primary of the transformer
R = Number of turns in the secondary of the current
transformer (Turns ratio, assuming one primary turn)
CSC = Current Scaling (parameter found in Current Menu
of Setup Page)
CSI = Current Source Instance (parameter found in Current
Menu of Setup Page)