Watlow 12LS Controller - Manual (Page 20)

3-6
3.1.4 RECOMMENDED CABLES P/N
Use these cables or equivalent.
|--------------------------------------------------------------|
¦ FUNCTION
¦ MFR P/N ¦ # of WIRE ¦
|--------------------------------------------------------------¦
¦ Analog Inputs
¦ Belden #9154 ¦ 2-20ga ¦
¦ ¦ Belden #8451 ¦ 2-22ga ¦
¦ ¦ ¦ ¦
¦ RTD Inputs ¦ Belden #8772 ¦ 3-20ga ¦
¦ ¦ Belden #9770 ¦ 3-22ga ¦
¦ ¦ ¦ ¦
¦ T/C Inputs ¦ T/C EXT.WIRE ¦ 2-wire ¦
¦ ¦ ¦ ¦
¦ Carbon Probe Input ¦ Belden #88760 ¦ 2-18ga ¦
¦ ¦ ¦ ¦
¦ ¦ ¦ ¦
¦ Digital PID Outputs ¦ Belden #9539 ¦ 9-24ga ¦
¦ and Digital I/O ¦ Belden #9542 ¦ 20-24ga ¦
¦ ¦ Ribbon Cable ¦ 50-wire ¦
¦ ¦ ¦ ¦
¦ Analog Outputs ¦ Belden #9154 ¦ 2-20ga ¦
¦ ¦ Belden #8451 ¦ 2-22ga ¦
¦ ¦ ¦ ¦
¦ Computer Communication ¦ Belden #9729 ¦ 4-24ga ¦
¦ --RS232,RS422,RS485, ¦ Belden #9730 ¦ 6-24ga ¦
¦ or 20ma-- ¦ Belden #9842 ¦ 4-24ga ¦
¦ ¦ Belden #9843 ¦ 6-24ga ¦
|--------------------------------------------------------------|
3.1.5 NOISE SUPPRESSION FOR DIGITAL OUTPUTS
When using the digital outputs from ANAFAZE multiloop controllers to energize dry contact electrical- mechanical
relays with inductive loads, generation of RFI may become a problem.
This problem may cause the display on the 8LS to blank out and then re-energize as if power had been momentary
turned off. It may also cause the CPU in the equipment to reset, thus losing the PID output levels. It may also damage
the digital output IC circuit, thus not being to energize the digital outputs. If, the IC circuit is damaged, factory repair
will be required.
The type of loads that may cause a problem are motor starters, alarm horns, etc. The RFI is generated upon opening of
the metallic relay contacts.
To correct the problem of RFI noise problems:
1. Use Solid State Relays (SSR) wherever possible in place of electrical-mechanical relays (E-M relays).
2. When using E-M relays, if possible do not mount them in the same panel as the ANAFAZE equipment.