Coates Electric Pool Heater, 36kw 208V Three Phase

The Coates 36kW 208V Three-Phase Electric Pool & Spa Heater (Model 32036CE / 32036CPH) is a high-output, commercial inline immersion heater engineered for high-demand municipal therapy pools, resort aquatic centers, swim schools, and athletic training plunge facilities operating on a standard 208V 3-phase/4-wire distribution network.

Balancing a 36kW thermal envelope across three phase legs allows this unit to deliver rapid heat-up rates at an operating current of approximately 100 Amps per line leg, avoiding the multi-circuit split feeds typically mandated on 240V single-phase systems of this wattage.

Electrical & Heating Performance

• Model Designation: Coates 32036CE / 32036CPH series (320 designates 3-Phase, 208V).

• 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: 208V AC, Three-Phase (3Ø), 3-pole / 3-wire plus ground (or 4-wire Wye), 60 Hz.

• Full Load Amperage (FLA): 99.9 Amps

  $$\text{FLA} = \frac{36,000\text{ W}}{208\text{ V} \times \sqrt{3}} = \frac{36,000}{360.26} \approx 99.93\text{ A}$$

• Overcurrent Protection (Breaker Sizing): Requires a dedicated 3-pole 125-Amp circuit breaker conforming to NEC 125% continuous-duty loading standards ($99.93\text{ A} \times 1.25 = 124.91\text{ A}$ minimum branch rating, standardizing on a 125A 3-pole breaker).

• Conductor Sizing: Minimum #1 AWG or #1/0 AWG THHN/THWN copper conductor (rated 75°C/90°C terminals, adjusted for ambient temperature, raceway fill, and conduit distance).

Construction & Safety Architecture

• Pressure Vessel: Heavy-gauge, welded cylindrical steel/stainless steel pressure vessel treated internally with a baked corrosion-resistant protective coating to endure continuous commercial water flow and aggressive sanitizing chemicals.

• Heating Elements: Screw-plug commercial immersion elements sheathed in premium Incoloy 800/825 or Titanium alloy, engineered to prevent chemical pitting, scaling, and high thermal stress.

• Cabinet & Enclosure: NEMA 1 industrial painted heavy-gauge steel cabinet with a removable front access panel for terminal inspections, staged 3-pole magnetic contactor servicing, and line terminations.

• Integrated Safety Controls:

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

  • Manual-reset High-Limit safety cutout set to de-energize the magnetic contactor control circuit at 122°F (50°C).

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

Hydraulic & Plumbing Specifications

• Plumbing Connections: Standard 1-1/2" NPT female inlet and outlet ports (typically adapted via Schedule 80 unions 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 safety flow switch and prevent localized thermal cavitation.

  • Maximum Flow Rate: 60 to 70 GPM (approx. 227 to 265 LPM); filtration loops operating at higher GPM 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 packaging with dense molded foam protection.

Estimated Temperature Rise Rates

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