Coates Electric Pool Heater, 57kw 240V Single Phase, Salt Water Application

The Coates 57kW 240V Single-Phase Electric Pool & Spa Heater for Salt Water Applications (Model 12457CES / 12457CPHS — featuring the "S" saltwater/corrosion-resistant package) represents the absolute maximum heating capacity available in Coates' single-phase commercial line. It is engineered for large commercial swim schools, municipal therapy pools, resort aquatic complexes, and athletic recovery facilities utilizing electrolytic salt chlorine generation systems (typically 2,500 to 4,500+ ppm TDS/NaCl).

At 57kW on a single-phase 240V supply, total continuous current reaches 237.5 Amps. Under NEC continuous-duty loading regulations requiring a 125% factor ($237.5\text{ A} \times 1.25 = 296.88\text{ A}$ minimum branch rating), a single feed would demand an impractically large 300A or 350A breaker and massive 350 kcmil conductors. Commercial installations invariably divide this load internally across three staged parallel branch circuits to align with standard commercial subpanels and raceway infrastructure.

Electrical & Heating Performance

• Model Designation: Coates 12457CES / 12457CPHS series (124 designates 1-Phase 240V; suffix designates Saltwater/Titanium package).

• Heating Capacity: 57 kW (57,000 Watts).

• Thermal Output: 194,492 BTU/hr ($57\text{ kW} \times 3,412.142\text{ BTU/kWh}$).

• Operating Voltage: 240V AC, Single-Phase (1Ø), 2-wire plus ground, 60 Hz.

• Total Full Load Amperage (FLA): 237.5 Amps

  $$\text{FLA} = \frac{57,000\text{ W}}{240\text{ V}} = 237.5\text{ A}$$

• Circuit & Overcurrent Protection Configurations:

  • Three-Circuit Split Configuration (Standard Field Specification): Three balanced 19kW heating stages:

    • Circuits 1, 2, & 3 (Each 19 kW / 79.17 A FLA): Each branch requires a dedicated 2-pole 100-Amp breaker ($79.17\text{ A} \times 1.25 = 98.96\text{ A}$ minimum branch rating), minimum #3 AWG or #2 AWG copper per circuit.

  • Dual-Circuit Split Configuration (Alternate Heavy Subpanel): Two balanced 28.5kW heating stages:

    • Circuits 1 & 2 (Each 28.5 kW / 118.75 A FLA): Each branch requires a dedicated 2-pole 150-Amp breaker ($118.75\text{ A} \times 1.25 = 148.44\text{ A}$ min), minimum #1/0 AWG or #2/0 AWG copper per circuit.

  • Single Feeder (Where Main Disconnect & Heavy Lug Subpanels Permit): Requires a dedicated 2-pole 300-Amp or 350-Amp circuit breaker with minimum 350 kcmil THHN copper.

Salt Water Construction & Metallurgy Upgrades

• Titanium / Incoloy 825 Sheathed Elements: Immersion elements are upgraded from standard low-grade alloys to Titanium or high-molybdenum/nickel Incoloy 825 sheathing to resist chloride-induced stress corrosion cracking (SCC), scale accumulation, and localized pitting from dissolved sodium chloride and electrolytic chlorination.

• Passivated / Barrier-Coated Pressure Vessel: Extended cylindrical pressure chamber fabricated from heavy-gauge 316L stainless steel or carbon steel lined with a specialized baked phenolic epoxy/fluoropolymer protective barrier, isolating the tank substrate from saline electrolytic degradation.

• Sacrificial Cathodic Protection: Equipped with an accessible sacrificial zinc or magnesium anode plug port to absorb galvanic action and mitigate stray current erosion in the salt plumbing loop.

• Corrosion-Inhibited Cabinet: Heavy-gauge NEMA 1 industrial painted enclosure finished with an anti-corrosion powder coating to prevent cabinet degradation in high-humidity, salt-vapor mechanical rooms.

Construction & Safety Architecture

• Cabinet & Enclosure: NEMA 1 industrial painted steel cabinet with a removable front panel for terminal inspections, multiple staged heavy-duty 2-pole magnetic contactor servicing, and field wire 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 (adapted via Schedule 80 CPVC unions into 2", 2-1/2", or 3" headers).

• Equipment Sequencing in Salt Systems: Must always be installed upstream of the electrolytic chlorine generator cell (separated by an inline corrosion-resistant check valve) to prevent hyper-concentrated chlorine gas or acidic pockets from pooling inside the heater vessel during pump shutdowns.

• Flow Rate Parameters:

  • Minimum Flow Rate: 30 to 35 GPM (approx. 114 to 132 LPM) required to trip the safety flow switch and prevent localized thermal cavitation across the multi-element array.

  • 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 90 to 98 lbs (approx. 40.8 to 44.5 kg).

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

• Packaged Shipping Weight: Approximately 105 to 118 lbs (approx. 47.6 to 53.5 kg) in heavy-duty reinforced corrugated packaging with dense molded foam protection.

Estimated Temperature Rise Rates

(Calculation: $\text{Rise (°F/hr)} = \frac{194,492\text{ BTU/hr}}{\text{Gallons} \times 8.34\text{ lbs/gal}}$, baseline heat-up rate assuming covered vessel without ambient radiation losses.)