Pool Main Pump Motor: Difference between revisions
→VFD Unit
Matt Parnell (talk | contribs) |
Matt Parnell (talk | contribs) |
||
| (5 intermediate revisions by the same user not shown) | |||
| Line 9: | Line 9: | ||
=== Starting and Stopping === | === Starting and Stopping === | ||
Prior to the spring of 2022, this was performed via pushbuttons on the motor starter. | |||
Further details will be posted once the VFD is brought up. | |||
=== Flow Adjustment === | === Flow Adjustment === | ||
Prior to the spring of 2022, pump flow was manually adjusted via the butterfly valve on the output side of the pump. | |||
Flow adjustment will be automatic with the VFD (details to follow). | |||
== Maintenance == | == Maintenance == | ||
| Line 35: | Line 37: | ||
== Variable Frequency Drive == | == Variable Frequency Drive == | ||
=== Background === | |||
Prior to the spring of 2022, the main pump motor was controlled by a Square D 8536 latching motor starter (relay). Start and stop operations were manually performed by pushbuttons. Adjustment of the flow rate was only possible by positioning the butterfly valve on the output side of the pump. | |||
Benefits to changing to the VFD include: | Benefits to changing to the VFD include: | ||
* | * The main pump 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 [[Pool Filter Tanks|sand filters]]. A constant flow rate can be assured until the strainer basket or filters become too clogged. The automation system is NOT required to operate the drive. In the event that the automation system is not operational (or remote VFD control is disabled), the VFD can be operated with start and stop pushbuttons in a manner very similar to that of the motor starter. | ||
* No need for the operator ( | * No need for the operator (the pool manager 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). | ** Violates best practices and/or health department requirements if it is too low (there is a required 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. | ** Causes channeling in the sand filters due if it is too high. This can lead to incomplete filtration (cloudy water) and requires opening and manually stirring tank sand to resolve. | ||
* Utility incentives will pay for a significant portion of the material cost. | * Utility incentives will pay for a significant portion of the material cost. At the time of the project, DTE reimbursed 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). | * 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. | * 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. | ||
| Line 55: | Line 55: | ||
There are some downsides, too: | There are some downsides, too: | ||
* | * The material cost (see the [[#Bill of Materials|bill of materials]]). This is managed by creative purchasing - utilizing refurbished and surplus materials where possible. | ||
* | * Some added complexity. | ||
* Added failure points - including the addition of sensitive electronics in a harsh environment. | * Added failure points - including the addition of sensitive electronics in a harsh environment (corrosive vapors and dust). | ||
An improvement in energy efficiency may be possible. However, it is not confirmed. Restricting the output flow on a centrifugal pump reduces the amount of work (pushing a lower volume weight of water). Data in the appendix below confirms this to a point. | An improvement in energy efficiency may be possible. However, it is not confirmed. Restricting the output flow on a centrifugal pump reduces the amount of work (pushing a lower volume weight of water). Data in the appendix below confirms this to a point. | ||
=== Theory of Operation === | === Theory of Operation === | ||
The sections | NOTE: The sections that follow are still under development. | ||
==== Reset ==== | ==== Reset ==== | ||
| Line 103: | Line 97: | ||
=== VFD Unit === | === VFD Unit === | ||
This section has been updated to alter its context from research to implementation. A majority of the data for "other" VFD units has been removed. | |||
Yaskawa GA50U2042ABA: | |||
* The 2042 model sized for "normal duty" (ND) 15 HP which is appropriate for variable torque (VT) applications (i.e. centrifugal pumps). | * The 2042 model sized for "normal duty" (ND) 15 HP which is appropriate for variable torque (VT) applications (i.e. centrifugal pumps). | ||
* Internal PCBs are conformally coated (IEC 60721-3-3, Class 3C2 for chemical gasses). <b>This is a huge plus!</b> | * Internal PCBs are conformally coated (IEC 60721-3-3, Class 3C2 for chemical gasses). <b>This is a huge plus!</b> | ||
| Line 131: | Line 111: | ||
* 391 W total loss @ 2 kHz, 42 A output. | * 391 W total loss @ 2 kHz, 42 A output. | ||
== | {| class="wikitable" | ||
!colspan="2"|Drive Catalog Code | |||
!Description | |||
!Comment | |||
|- | |||
!Product Series | |||
|GA50 | |||
| | |||
| | |||
|- | |||
!Region Code | |||
|U | |||
|Americas | |||
| | |||
|- | |||
!Input Power Supply Voltage | |||
|2 | |||
|Three-Phase AC 200 V Class | |||
| | |||
|- | |||
!Rated Output Current | |||
|42 | |||
|42 A | |||
| | |||
|- | |||
!EMC Noise Filter | |||
|A | |||
|No Internal EMC Filter | |||
| | |||
|- | |||
!Enclosure Protection Design | |||
|B | |||
|IP20/UL Open Type | |||
| | |||
|- | |||
!Environmental Specification | |||
|A | |||
|Standard | |||
| | |||
|} | |||
==== Prior Considerations ==== | |||
VFDs from various manufacturers were considered during the evaluation process. In particular, the following other drives were evaluated: | |||
* ABB ACS310-03U-50A8-2+J400 | |||
* Automation Direct GS23-2015 | |||
* Automation Direct GS4-2015 | |||
=== Line Reactor === | === Line Reactor === | ||
| Line 158: | Line 166: | ||
A 3% impedance reactor absorbs transients and prevents nuisance tripping of drives in most applications and is typical for the line side. A 5% impedance reactor can be used if the harmonic content is severe or if IEEE519 recommendations should be met. The reactor impedance magnitude is said to be equal to the voltage drop. | A 3% impedance reactor absorbs transients and prevents nuisance tripping of drives in most applications and is typical for the line side. A 5% impedance reactor can be used if the harmonic content is severe or if IEEE519 recommendations should be met. The reactor impedance magnitude is said to be equal to the voltage drop. | ||
For 37 FLA (motor rating). Assume the VFD has about 97% efficiency (given loss is 391 W @ | For 37 FLA (motor rating). Assume the VFD has about 97% efficiency (given loss is 391 W @ 42 A). | ||
{| class="wikitable" | {| class="wikitable" | ||