Coates Electric Pool Heater, 36kw 240V Single Phase, Salt Water Application

The Coates 36kW 240V Single-Phase Electric Pool & Spa Heater for Salt Water Applications (Model 12436CES / 12436CPHS — featuring the "S" saltwater/corrosion-resistant package) is a heavy-duty, high-capacity inline immersion heater engineered for large commercial swim spas, municipal therapy pools, resort plunge pools, and wellness facilities operating with electrolytic salt chlorine generation systems (typically 2,500 to 4,500+ ppm TDS/NaCl).

At 36kW on a single-phase 240V supply, total continuous current reaches 150 Amps. To adhere to NEC continuous-duty loading regulations and avoid massive single-conductor pulls, commercial installations split this demand internally across two balanced 18kW branch circuits.

Electrical & Heating Performance

• Model Designation: Coates 12436CES / 12436CPHS series (124 designates 1-Phase 240V; suffix designates Saltwater/Titanium package).

• 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), 2-wire plus ground, 60 Hz.

• Total Full Load Amperage (FLA): 150.0 Amps

  $$\text{FLA} = \frac{36,000\text{ W}}{240\text{ V}} = 150.0\text{ A}$$

• Circuit & Overcurrent Protection Configurations:

  • Split Dual-Circuit Configuration (Standard Field Specification): Two balanced 18kW heating stages:

    • Circuit 1: 18 kW / 75.0 Amps FLA $\rightarrow$ Requires a dedicated 2-pole 100-Amp breaker ($75.0\text{ A} \times 1.25 = 93.75\text{ A}$ min), minimum #3 AWG or #2 AWG copper.

    • Circuit 2: 18 kW / 75.0 Amps FLA $\rightarrow$ Requires a dedicated 2-pole 100-Amp breaker ($75.0\text{ A} \times 1.25 = 93.75\text{ A}$ min), minimum #3 AWG or #2 AWG copper.

  • Single Feeder Configuration (Where Panel and Lugs Permit): Requires a dedicated 2-pole 200-Amp circuit breaker rated for continuous duty ($150.0\text{ A} \times 1.25 = 187.5\text{ A}$ minimum branch rating, standardizing on a 200A breaker) with minimum #3/0 AWG or #4/0 AWG THHN copper.

Salt Water Construction & Metallurgy Upgrades

• Titanium / Incoloy 825 Sheathed Elements: Immersion elements are upgraded from standard alloys to Titanium or high-nickel/high-molybdenum 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, dual 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" or 2-1/2" 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: 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 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.)