NSF currently tests pool and spa pumps under NSF/ANSI Standard 50 to the same requirements and number of tests whether the pumps
Are single speed or include variable speed motor control functions. NSF 50 currently requires testing pumps for pump performance at one speed.
In recent NSF 50 Joint Committee meetings there was much discussion related to multispeed,(ie 2-speed, 3-speed, and or variable speed)
pumps and external control systems. From those past meetings, NSF has some open NSF/ANSI Standard 50 Task Group work to finalize
additional testing criteria to NSF 50 relative to multispeed pumps for:
1) testing pump curves at more than full speed (ie also test at 75%, 66%, 50%, and/or lowest pump speed) for a total of 3 or 4 pump speeds for pump performance curve,
2) testing of pump flow rate accuracy for pump systems that may infer, read out, or provide a pump flow rate output,
3) testing of the method for testing maximum pump flow rate and marking, etc.
4) testing for sound emission
Related to the above pump items, there was an issue of urgency for public health officials and facility operators that may seek
The addition of informational content relative to use of variable frequency drives or variable speed pumps at existing facilities.
NSF was contacted by Steve Barnes and about this issue. Steve asked if the issue could be sent to the NSF 50 JC for review and
Potential incorporation of the informational annex content.
NSF staff reviewed the submitted information. We had a few teleconferences and shared technical discussions and calculations.
This culminated in some potential content for an informational annex content to be considered by the NSF/ANSI Standard 50 JC.
NSF staff feels this information is ready for circulation to the NSF 50 JC in order to add it to NSF/ANSI Standard 50. But the other original
Joint Committee Pump Issues should be moved to a task group discussion for action. |
