ITT Goulds Pumps V 3298, Инструкции по установке, эксплуатации и обслуживанию

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APPENDIX IV
POWER MONITORS
CONDENSED POWER MONITOR USER GUIDE
ITT Goulds Pumps offers various power monitoring
devices which have been designed to protect pumps from
dry-running, running against a closed discharge valve,
and running outside of the recommended operating region
for specific pump sizes, speeds, and impeller diameters.
Power monitors were designed to detect power relative to
load which is a linear function as opposed to measuring
amperage relative to load which is a parabolic function.
The linear characteristic of measuring power vs. load
enhances sensitivity at low power conditions where
increments in power are critical. See
Fig. IV-1 for
comparison of power measurements vs. amperage
measurements. Quite simply, a properly adjusted and
installed power monitor is an insurance policy for
securing extended pump life.
The following summarized concepts will assist in
effectively selecting and properly calibrating power
monitors used to protect pumps.
1. Read your power monitor installation instructions
and wiring diagram before attempting to calibrate the
unit.
2. Understand your pump’s recommended operating
envelope as provided by ITT Goulds Pumps.
3. Understand your systems requirements and
limitations.
4. Understand the full range of your operating duty,
including power requirements at the rated minimum
and maximum flow conditions.
5. If only small fluctuations occur between the rated
point and trip points (less than 15% of the total motor
horsepower available), then the Integra Motor
Minder should not be used. In this case, use either
the Emotron or Load Controls unit as they can
detect to approximately 1% changes in horsepower.
6. Understand the relationship and limitations of item
numbers 2, 3, and 4 as an integrated functional
system.
7. Identify potential failures that would most likely be
characteristic of your specific process and the pump
type selected.
8. Understand the power scope and torque scope of the
selected electric motor.
9. A complete analysis of the above concepts will
define a safe operating range for your specific
system.
10. When feasible, further define your operating range to
run as close to BEP (best efficiency point) as
practical.
11. Select single trip unit or dual trip unit as practical for
your specific system.
12. Set low power trip point at the power draw required
when operating at the manufacturer’s recommended
minimum flow or higher, yet less than the normal
operating point.
13. Set the high trip point at the power draw required
when operating at the manufacturer’s recommended
maximum flow or lower, or at flow rate that will
prevent cavitation.
14. When using dual trip power monitors, select high and
low trip points designed to protect your specific
system within the recommended pump operating
region defined by ITT Goulds Pumps. This method
will create boundaries for a safe pump operating
envelope.
3298 Family Rev. 4/07
139
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Fig. IV-1