Ground loops, Power connections, Power connections 23 – Watlow CPC400 User Manual
Page 37
CPC400 Series User’s Guide
Chapter 2: Installation
Doc. 0600-2900-2000
Watlow Anafaze
23
Ground Loops
Ground loops occur when current passes from the process
through the controller to ground. This can cause instru-
ment errors or malfunctions.
The best way to avoid ground loops is to minimize unneces-
sary connections to ground. Do not connect any of the fol-
lowing terminals to each other or to earth ground:
•
Power supply dc common
•
TB1 terminals 5, 6, 11, 12 (analog common)
•
TB1 terminal 17 (reference voltage common)
•
TB1 terminals 23, 24 (communications common)
•
TB2 terminal 2 (dc power common)
Power Connections
This section explains how to make power connections to the
CPC400 and the TB50.
Figure 2.11 CPC400 Series Controller with
TB18
Figure 2.12 CPC400 Series Controller with
TB50
TB2
(to power
supply)
TB1
(to signal
inputs
TB18
(to digital
outputs)
SCSI-2
(to TB50)
TB2
(to power
supply)
TB1
(to signal
inputs