IOM CRUZcontrol®
P/N: 90480009
Revision Date: 03/18/2019
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Use of 115 VAC controls with all Function Modules
Important information regarding the use of 115 VAC controls:
These Function Modules will accept 115 VAC level control inputs. There are some cautions that must
be observed to avoid Function Module hardware failure.
•
Function Module signal inputs are protected against 500 volt spikes. 115 VAC control signal
wiring run in conduit along with higher voltage motor wiring could experience voltage spikes that
exceed the 500 volt limit. This can be prevented by running control wiring in separate conduit
from motor wiring. Additional protection for the Function Module inputs can be achieved by
using an MOV (metal oxide varistor) placed across the input terminals within the Function
Module. Suggestions of suitable MOV’s would include Panasonic ERZV07D241 or Littlefuse
V250LA2.
Long conduit runs with motor wiring for multiple motors, and the use of variable frequency drives, all
contribute to electrical noise, with a good potential for high voltage spikes. If there is any doubt, the
control signals to the Function Modules should be run in conduits separate from motor wiring.
•
The Function Module signal inputs have high impedance. When connected to some output
devices, such as some PLC triac outputs, the inputs could sense an on state even if the output
connected to it is not on. This can be corrected by adding additional loading to the output. This
can be done by adding a loading resistor, placed across the output terminals. Do not put this
resistor inside of the Function Module. The size and wattage rating of the resistor would depend
on the output characteristics. A typical value would be 10,000 ohms (10K ohms) and 2 watts.
The resistor would dissipate 1.32 watts at 115 VAC, so it will get warm.
