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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

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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)