Coates Electric Pool Heater, 36kw 240V Single Phase

The Coates 36kW 240V Single-Phase Electric Pool & Spa Heater (Model 12436CE / 12436CPH) represents an extreme-output commercial electric immersion configuration engineered for large municipal hydrotherapy pools, wellness resort spas, swim schools, and specialized commercial aquatic tanks where gas infrastructure is unavailable or code-prohibited.

Operating 36kW on a standard 240V single-phase electrical supply pushes current draw to heavy industrial thresholds, mandating staged magnetic contactors, segregated internal branch circuits, and dedicated subpanel distribution to satisfy National Electrical Code (NEC) continuous-duty mandates.

Electrical & Heating Performance

• Model Designation: Coates 12436CE / 12436CPH series.

• Heating Capacity: 36 kW (36,000 Watts).

• Thermal Output: 122,837 BTU/hr ($36\text{ kW} \times 3,412.142\text{ BTU/kWh}$).

• Operating Voltage: 240V AC, Single-Phase (1Ø), 60 Hz.

• Full Load Amperage (FLA): 150.0 Amps ($36,000\text{ W} / 240\text{ V} = 150.0\text{ A}$).

• Overcurrent Protection (Breaker Sizing): Requires a combined continuous-duty branch circuit protection rating of 190 to 200 Amps under NEC continuous-duty loading ($150.0\text{ A} \times 1.25 = 187.5\text{ A}$ minimum branch rating).

  • Subpanel & Multi-Feed Configuration: Because 150A single-phase continuous load exceeds standard single-lug heating contactor limits, the unit is configured for split multi-circuit supply:

    • Three independent 70A / 2-Pole branch circuits (each feeding a 12kW heating bank at 50.0A continuous load, requiring minimum 62.5A breaker sizing), OR

    • Two independent 100A / 2-Pole branch circuits (each feeding an 18kW heating bank at 75.0A continuous load, requiring minimum 93.75A breaker sizing).

• Conductor Sizing (Copper Only, 75°C/90°C THHN/THWN):

  • Three-Circuit Split: Three sets of #4 AWG copper conductors.

  • Two-Circuit Split: Two sets of #1 AWG or #1/0 AWG copper conductors.

  • Single Feeder Subpanel Supply: Minimum #3/0 AWG or #4/0 AWG copper feeding a dedicated localized distribution panel.

Construction & Safety Architecture

• Pressure Vessel: Heavy-gauge, welded cylindrical steel/stainless steel pressure vessel featuring a high-temperature baked internal protective lining to endure elevated water velocities and aggressive commercial chemical sanitizers.

• Heating Elements: Screw-plug commercial immersion elements sheathed in premium Incoloy 800/825 or Titanium alloy to resist chemical pitting, scale accumulation, and extreme watt-density thermal stress.

• Cabinet & Enclosure: NEMA 1 industrial heavy-gauge powder-coated steel enclosure with hinged/removable front access panels for element replacement, multi-stage contactor inspection, and terminal torque verification.

• Integrated Safety Controls:

  • Dual-dial adjustable thermostatic controller calibrated up to 104°F (40°C) for commercial spa safety.

  • Manual-reset High-Limit safety cutout switch calibrated to disconnect control power at 122°F (50°C).

  • Pressure/flow-interlock switch preventing heating contactors from pulling in during zero-flow, pump loss, or deadhead conditions.

Hydraulic & Plumbing Specifications

• Plumbing Connections: Standard 1-1/2" NPT female inlet and outlet ports (typically plumbed with Schedule 80 union transitions into 2" or 2-1/2" CPVC headers).

• Flow Rate Parameters:

  • Minimum Flow Rate: 20 to 25 GPM (approx. 76 to 95 LPM) required to trip the internal safety flow switch and prevent flash-boiling.

  • Maximum Flow Rate: 60 to 70 GPM (approx. 227 to 265 LPM); higher circulation filtration loops mandate an external plumbed bypass manifold.

• Maximum Working Pressure: 60 PSI (approx. 4.14 bar).

Dimensions, Net Weight & Shipping Weight

• Unit Dimensions: Approximately 24.0" L × 12.0" W × 16.5" H (approx. 61.0 cm × 30.5 cm × 41.9 cm).

• Net Unit Weight: Approximately 74 to 82 lbs (approx. 33.6 to 37.2 kg).

• Packaged Shipping Dimensions: Approximately 26" L × 15" W × 19" H.

• Packaged Shipping Weight: Approximately 88 to 98 lbs (approx. 39.9 to 44.5 kg) in heavy-duty reinforced corrugated carton with high-density molded foam bracing.

Estimated Temperature Rise Rates

(Calculation: $\text{Rise (°F/hr)} = \frac{122,837\text{ BTU/hr}}{\text{Gallons} \times 8.34\text{ lbs/gal}}$, baseline thermal absorption rate assuming covered surface without ambient radiation losses.)