Pool Main Pump Motor: Difference between revisions
Jump to navigation
Jump to search
no edit summary
Matt Parnell (talk | contribs) |
Matt Parnell (talk | contribs) No edit summary |
||
| Line 13: | Line 13: | ||
=== Flow Adjustment === | === Flow Adjustment === | ||
The pump flow is adjusted via the butterfly valve on the | The pump flow is adjusted via the butterfly valve on the output side of the pump. The flow rate must be periodically adjusted via this valve as debris in the strainer basket and sand filters provides additional resistance. | ||
In the future, a VFD may be used to reduce the motor speed, eliminating the need for manual adjustment via a valve. | In the future, a VFD may be used to reduce the motor speed, eliminating the need for manual adjustment via a valve. | ||
| Line 31: | Line 31: | ||
<b>IMPORTANT:</b> At this time, this section is for investigation purposes only. It has not been determined when/if a VFD will be implemented. | <b>IMPORTANT:</b> At this time, this section is for investigation purposes only. It has not been determined when/if a VFD will be implemented. | ||
An | ==== Justification ==== | ||
As of Fall 2021, the pump is controlled by a Square D 8536 latching motor starter (relay). The pump is manually operated via start and stop pushbuttons. The flow rate is adjusted via the butterfly valve on the output side of the pump. | |||
Benefits to changing to the VFD: | |||
* Motor speed can be automatically adjusted (via the [[Pool Systems Automation|automation system]]) to compensate for changes in flow rate due to the state of the strainer basket and sand filters. A constant and flow rate can be assured until the strainer basket or filters become too clogged. | |||
* No need for the operator (managers or B&G personnel) to regularly adjust the flow rate due to changing conditions. An improper flow rate: | |||
** Violates best practices and/or health department requirements if too low (minimum number of complete water turn-over cycles per 24 hour period). | |||
** Causes channeling in the sand filters due if too high. This can lead to incomplete filtration (cloudy water) and requires opening and manually stirring tank sand to resolve. | |||
* Improved energy efficiency. If the pump does not need to run at full speed to produce the desired flow rate, it will be electrically reduced. This can be a more efficient approach than choking the output flow via the butterfly valve. | |||
* Utility incentives will pay for a significant portion of the material cost. As of 2022, DTE will reimburse up to $900 for a 15 HP VFD. | |||
* Enhanced safety with the addition of two emergency stop buttons, including one at the gallery level (near the pump). | |||
* Reduced stress on the mechanical system during startup as the motor speed can be ramped up rather than instant-on. This prevents "hammering" that can occur from an abrupt start. | |||
* Improved fault detection. The drive can detect shorts, over-current events, low voltage, phase loss, etc. The existing configuration relies solely upon fuses, which may not offer the same level of protection. | |||
There are some downsides, too: | |||
* Material cost (see the [[#Bill of Materials|bill of materials). | |||
* Added complexity. | |||
* Added failure points - including the addition of sensitive electronics in a harsh environment. | |||
=== Requirements === | === Requirements === | ||
| Line 68: | Line 88: | ||
=== VFD Unit === | === VFD Unit === | ||
An Automatic Direct DURApulse GS23-2015 VFD has been chosen over multiple competing options. The feature set and pricing is very competitive. | |||
==== Configuration ==== | ==== Configuration ==== | ||