Artesian Spas - A spa is only as good as its parts.
Switchless Motors
The revolutionary switchless motors used in Artesian Spas drive high-water volume
pumps that are long-lasting and virtually trouble-free. The switchless motor
design does not require a mechanical switch to take it from the start position to run
position, which greatly increases the efficiency of the motor. It also diminishes
operating noise, such as the vibration and electrical noise heard with conventional
motors. An added bonus of the switchless motor is this design requires from 10 to
16 fewer parts than a conventional motor, which means many
potentially problematic components
have been eliminated. The life of
our switchless motor can be
measured in tens of years
instead of hundreds of hours. Back to Construction Features
>>
What are the main design differences between a switched and switchless design? Overall, the focus of the switched v. switchless design debate is around two-speed designs. Switched designs include split phase, cap start, cap start/cap run. The permanent split capacitor or PSC design is switchless.
There are three motor designs that can be considered:
Pole Changer – motor contains high and low main and high start only; motor only starts using high speed start after which the switch removes the start and energizes high or low main.
PSC/Split Phase – motor contains high and low main as well as high and low start; motor with energize only the main/start combination that is desired; low speed starting torque is comparable with high speed.
PSC/PSC – motor contains high and low main as well as high and low start; motor will energize only the main/start windings that are desired; low speed starting torque is significantly less that high speed.
Conventional Pole Changer
Switched motors utilize a centrifugal mech and switch to disengage the start winding or capacitor from the circuit.
Mech has been reliability tested to over 1,000,000 cycles and switch to between 100,000 and 1,000,000, depending on switching currents.
Switch may be see 40-45A/230V in high output designs, leading to reduced switch life.
Outputs ranging from 1/15HP to 4.0HP.
Can start on high speed or low speed though not both.
Low Speed Switched
A revised switched design has been developed to eliminate degraded switch life.
New design involves four windings, including high and low mains, high and low starts.
High speed is switchless (PSC), while low speed is split phase.
Switch contacts only “see” current from low speed (1/8-1/2HP) portion of motor, reducing switching amps from 40-45A/230V to 5-10A/230V.
Starting torque is roughly equivalent between high and low speed.
Motor may start on high or low speed based on individual mains and starts.
Speed may or may not be specified with design – based on customer preference.
Switchless Design
Switchless motor actually contains a switch body without contacts, though only for line power connections.
Both high speed and low speed are PSC, eliminating need for mech/switch.
Eliminates potential for premature mech/switch failure.
Speed reduction relay is utilized to eliminate unpleasant switching noises from high to low speed.
Relay is also used to electrically isolate high and low speeds – elimates motor/generator affect.
Function / Characteristic
Pole Changer
PSC/Split Phase
Switchless
Output
Up to 4.0 Motor HP
Up to 4.0 Motor HP
Up to 4.0 Motor HP
Frame Size
NEMA 48 / 56 Frame
NEMA 48 / 56 Frame
NEMA 48 / 56 Frame
Construction
TEFC / DP
TEFC / DP
TEFC / DP
Electrical Design
KCR - Cap Start/Cap Run, KH - Split Phase, KC - Cap Start
PSC High Speed, Split Phase Low Speed
PSC - Permanent Split Capacitor
Ventilation System
Backflow / Forward-flow Shaft Mounted Fan
Backflow / Forward-flow Shaft Mounted Fan
Backflow / Forward-flow Shaft Mounted Fan
High Speed Advantages / Disadvantages
High efficiency in KCR, high output potential, high switching leading to decrease switch contact life
High efficiency, high output potential, no conventional mechanical switch/mech necessary
High efficiency, high output potential, no conventional mechanical switch/mech necessary
Low Speed Advantages / Disadvantages
Excellent starting torque through utilization of high speed start, moderate efficiency based on split phase design
Excellent starting torque based on individual split phase start, value matches that of high speed, moderate efficiency
High efficiency, low amp draw, no switch/mech necessary, significantly reduced starting torque - potential for "stuck" pumps
Potential Switching Failure Mode
1. Switch Contact Burnout
None
None
2. Mech Spring/Weight/Backplate Failure
Potential Pump Failure Modes
None
None
Slow / No Start on Low Speed Created by Marginal Starting Torque on Low Speed at Undervoltage
Rotor Resistance
Low - Cap Utilized for Starting Torque
Low
High - Required to Provide Sufficient Low Speed Starting Torque
