Allen-Bradley 1404-M4, User Manual

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1 Publication 1404-UM001D-EN-E - October 2004
Appendix
E
Frequently Asked Questions
Q. Can I program the power monitor through the display?
A. Yes. All programmable attributes can be accessed and programmed
through the display module.
Q. Do I need a display module?
A. All features of the monitor can be accessed and programmed
through the communication port(s). The display module is a highly
recommended option.
Q. Can I power the power monitor from the source being
monitored?
A. Yes, but it’s not advisable. Assuming a voltage match, logging of
power outages and voltage phase loss anomalies would be difficult,
if not impossible.
Q. What determines what information I get using RIO block
transfers?
A. The word length of the block transfer.
Q. My Volt and Amp readings look good, but why are my power
numbers way off?
A. One or more Current/Voltage transformers are wired with reverse
polarity or improper phase sequence.
Q. What size fuses do I use for my voltage inputs?
A. Size the fuses to the National Electric Code for the size of the wire
being used.
Q. Why do I need shorting terminal blocks for the current
transformers?
A. If for any reason, the meter’s current transformer wires are removed
or disturbed to cause an open circuit in the Current Transformers
secondary while primary current is applied, a hazardous voltage
will occur, which may cause personal injury, death, property
damage, or economic loss.
Q. Can I monitor several loads from one monitor?
A. It is not advisable to switch current transformer inputs. Besides the
need for special current transformer switches, confusion over
logged data and setpoint activation would also have to be
considered.
Allen-Bradley HMIs