Rockwell Automation 700-HX Multifunction Digital Timer - Manual (Page 37)

Publication 700-UM002B-EN-D - June 2010
7-2 Precautions
Power Supplies Make sure that the voltage is applied within the specified range, otherwise the
internal elements of the Timer may be damaged.
When turning the power ON and OFF, input signal reception is possible,
unstable, or impossible as shown in the diagram below.
Turn the power ON and OFF using a relay with a rated capacity of 10 A
minimum to prevent contact deterioration due to inrush current caused by
turning the power ON and OFF.
Apply the power supply voltage through a relay or switch in such a way that
the voltage reaches a fixed value immediately, otherwise they may not be reset
or a timer error may result.
Be sure that the capacity of the power supply is large enough, otherwise the
Timer may not start due to inrush current (approx. 5 A) that may flow for an
instant when the Timer is turned on.
Make sure that the fluctuation of the supply voltage is within the permissible
range.
Timer Control with Power
Start To allow for the startup time of peripheral devices (sensors, etc.), the 700-HX
starts timing operation between 200 ms…260 ms after power is turned ON.
For this reason, in operations where timing starts from power ON, the time
display will actually start from 250 ms. If the set value is 249 ms or less, the
time until output turns ON will be a fixed value between 200…250. (Normal
operation is possible for set value of 250 ms or more.) In applications in which
a set value of 249 ms or less is required, use start timing with signal input.
When the 700-HX is used with power start in F mode (i.e., accumulative
operation with output on hold), there will be a timer error (approximately
100 ms each time the 700-HX is turned ON) due to the characteristics of the
internal circuitry. Use the 700-HX with signal start if timer accuracy is
required.
Power
supply
Input Impossible
Unstable
Possible Impossible Unstable
200 ms 0 to 50 ms 5 ms 0 to 500 ms
ON
OFF