Coates Electric Pool Heater, 18kw 600V Three Phase, Salt Water Application

The Coates 18kW 600V Three-Phase Electric Pool & Spa Heater for Salt Water Applications (Model 36018CES / 36018CPHS — featuring the "S" saltwater/corrosion-resistant package) is engineered for commercial hydrotherapy tanks, athletic recovery plunge pools, and resort aquatic spas operating with electrolytic salt chlorine generation systems (typically 2,500 to 4,500+ ppm TDS/NaCl) on a standard Canadian 600V 3-phase/3-wire or 4-wire electrical distribution network.

Operating 18kW across 600V 3-phase draws 17.3 Amps per phase (compared to 50.0 Amps on 208V 3-phase and 75.0 Amps on single-phase 240V). The factory saltwater configuration provides upgraded metallurgy and protective tank barrier coatings to withstand aggressive saline electrolytes, preventing chloride pitting and stress corrosion cracking.

Electrical & Heating Performance

• Model Designation: Coates 36018CES / 36018CPHS series (360 designates 3-Phase 600V; suffix designates Saltwater/Titanium package).

• Heating Capacity: 18 kW (18,000 Watts).

• Thermal Output: 61,418 BTU/hr ($18\text{ kW} \times 3,412.142\text{ BTU/kWh}$).

• Operating Voltage: 600V AC, Three-Phase (3Ø), 3-pole / 3-wire plus ground (or 4-wire Wye), 60 Hz.

• Full Load Amperage (FLA): 17.3 Amps

  $$\text{FLA} = \frac{18,000\text{ W}}{600\text{ V} \times \sqrt{3}} = \frac{18,000}{1,039.23} \approx 17.32\text{ A} \rightarrow 17.3\text{ A}$$

• Overcurrent Protection (Breaker Sizing): Requires a dedicated 3-pole 25-Amp circuit breaker (600V-rated) conforming to CEC/NEC 125% continuous-duty loading standards ($17.32\text{ A} \times 1.25 = 21.65\text{ A}$ minimum branch rating, standardizing on a 25A 600V 3-pole breaker).

• Conductor Sizing: Minimum #10 AWG copper conductor (rated 600V, 75°C/90°C THHN/THWN/RW90; adjusted for ambient derating and conduit run length).

Salt Water Construction & Metallurgy Upgrades

• Titanium / Incoloy 825 Sheathed Elements: Immersion elements are upgraded from standard 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, 600V-rated 3-pole magnetic contactor servicing, and field wire terminations.

• Internal Control Circuit: Factory-installed step-down control transformer (600V primary to 120V/24V secondary) powering the thermostatic control circuit and safety interlocks.

• 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: 15 to 20 GPM (approx. 57 to 76 LPM) required to trip the internal safety flow switch.

  • 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 19.5" L × 10.0" W × 14.5" H (approx. 49.5 cm × 25.4 cm × 36.8 cm).

• Net Unit Weight: Approximately 50 to 56 lbs (approx. 22.7 to 25.4 kg).

• Packaged Shipping Dimensions: Approximately 22" L × 13" W × 17" H.

• Packaged Shipping Weight: Approximately 62 to 70 lbs (approx. 28.1 to 31.8 kg) in heavy-duty reinforced corrugated carton packaging.

Estimated Temperature Rise Rates

(Calculation: $\text{Rise (°F/hr)} = \frac{61,418\text{ BTU/hr}}{\text{Gallons} \times 8.34\text{ lbs/gal}}$, baseline heat-up rate assuming covered vessel without ambient radiation losses.)