Pool Main Pump Motor

The main pool pump motor at the facility (as of August 2021) is a Leeson Model C254T17DK13A (catalog #199987.00). It is rated for 15 HP (11 kW), 37 FLA @ 230 VAC. It is inverter duty rated (confirmed by the local manufacturer's rep) with a 10:1 PWM ratio (60 Hz, 1770 RPM down to 6 Hz, 177 RPM).

It has a month/year manufacturing designation of "H2016" - presumably corresponding with August (H=8) 2016. This makes sense, as the pump was noted to have been replaced in early 2017.

Wiring and Fuse Protection

The existing motor is fed by 3 x TBD (#10 AWG GND). Fused with 3 x FRN-R-60 (60 A) fuses.

Power Factor Correction Capacitor (PFCC)

At present (as of August 2021), no power factor correction capacitor (PFCC) is in use. It was decided that given cost priorities, a PFCC would not offer sufficient payback to justify its purchase.

Myron Zucker was contacted in August 2020 and provided two options, both rated for 240 VAC, 5 kVAr, 3-phase, 60 Hz:

• KNM23005-3 (NEMA 12 for indoor use, 14" H x 9.25" W x 5.25" D)
• KNM23005-3N3 (NEMA 3R suitable for outdoor use, 16" H x 12" W x 6" D)

Applying a 5 kVAr PFCC would reduce the FLA from 37 A to 31 A. This would reduce i-squared-R losses by 6 A. Actual losses are then based upon the cable run.

Variable Frequency Drive (VFD)

IMPORTANT: At this time, this section is for investigation purposes only. It has not been determined when/if a VFD will be implemented.

Requirements

• It's likely that the drive could be exposed to greater than 40 °C (104 °F) operation. A very hot summer day, plus additional heat contained within the building and/or enclosure could easily place the ambient operating range into the 40 °C to 50 °C (122 °F) range. This temperature is also referred to as the Maximum Enclosure Internal Temperature (MEIT) in some literature.

High-Leg Delta

A major issue/question remains to be answered: Can any VFD reliably operate with high-leg delta service as is present at the club?

Safety

A safety relay (reset and E-stop circuits) and additional contactor (maybe two contactors w/o STO) are likely required.

Options

The following options are under consideration (still a work in progress). All drives are sized to drive a 15 HP motor, 230 VAC three-phase.

Unless otherwise noted, all support Modbus RTU (via RS-485).

• Fuji Electric FRN0047C2S-2U
  • 47.0 FLA (21 % margin for 37 FLA)
  • 10.24" H x 8.66" W x 7.48" D
  • No STO
• Hitachi WJ200-110LF
  • 56.0 FLA VT (34 % margin for 37 FLA)
  • 11.65" H x 7.09" W x 6.89" D
  • With STO
  • DC Reactor: DCL-L-11
  • Input Side AC Reactor: ALI-22L2
  • Input Side Noise Filter: NF-L60
  • Radio Noise Filter: ZCL-A (Zero-Phase Reactor) or CFI-L (Capacitor Filter)
• DURApulse (Automation Direct) GS20 Series GS23-2015 ($567.50)
  • 51 FLA VT (27 % margin for 37 FLA)
  • Frame Size "E": 9.84" H x 5.12" W x 7.28" D
  • Clearance
  • With STO (TUV Certified)
  • Conduit Box: GS20A-N1E ($29)
  • EMC Filter & Zero-Phase Reactor: RF008X00A
  • Input Fuse: 110 A, TJN110 (Fast-Acting Class T) or JHL110 (Edison Class J)
  • Line/Load Reactor: LR-2020 ($181.00)
  • AC Output Filter (VTF): VTF-246-NRS

Wiring

Shielded VFD cabling may be required to contain high-frequency emissions. Automation Direct has #8 AWG 4-conductor XLPE insulated shielded cable, rated for 50 A at 75 °C (NEC 310.15 (B), assumes 30 °C ambient) for $8.08/ft (August 2021 pricing). The cable is made in USA by Southwire. This cable has an OD of 0.87 inches and minimum bend radius of 10 inches. Calculations suggest a 1-1/4" conduit may be necessary to pull a cable of this diameter with adequate fill margin. The existing PVC conduit appears to be about 3/4" (to confirm), which would need to be replaced.

A load reactor likely will not be used, nor does it necessarily eliminate the need for shielded VFD cabling.

Configuration

Subject to further review:

• Variable Torque (VT) for pump control (power is proportional to the cube of the speed)

DURApulse GS23-2015

• For 75% load at 50 °C, no de-rating is necessary up to xx kHz.