Power Quality and Drives LLC

Medium Voltage Products

Medium Voltage Transformers, Variable Frequency Drives and Switchgear

Motor Starters and Other Motor Control Products

Products by LS Industrial Systems

Open Starters For Panel Mounting


Lug Kits for 100 to 800 Amp Contactors and Starters


Enclosed Starters, UL Type 1 Enclosure, w/Start and Stop Pushbuttons

Enclosed Starters, UL Type 1 Enclosure, with No Pushbuttons

UL Type 1 Enclosed Starters w/Hand-Off-Auto and Control Power Transformer

Enclosed Starters, Type 4/12 Enclosure, w/Start and Stop Pushbuttons

Enclosed Starters, Type 4/12 Enclosure, w/ HOA and CPT

Combination Starters w/Motor Circuit Protector Disconnect and HOA

Explosion Proof Starters

     with Motor Circuit Protector
     with Ground Fault Protection

Wye-Delta Starters

Part-Winding Starters

Manual Motor Starters

Enclosures: Types 1, 3R, 4, 4X, 7, 12

Combination Starters with
      Circuit Breaker Disconnect
      Disconnect with UL Type E Motor Circuit Protector, Contactor and
      Overload Relay
      Disconnect with UL Type F Motor Circuit Protector and Contactor,
      Motor Circuit Protector is used for overload protection

Overload Relays
      Bi-metallic with adjustable amp range

   Solid State Overload Relays

   Current Transformers for use with Solid State Overload Relays or other applications

Variable Frequency Drives
   Single phase input is available up to approximately 40 HP
   460 VAC, three phase input up to 1300 HP
   230 VAC, three phase input up to 800 HP
   2 or 3 Contactor Bypass
   Disconnect, Input Reactor, Output Filter,
   Passive Harmonic Filter, Communications 
   Enclosed VFDs: Types 1, 3R, 4, 12
   NEMA 7 enclosed up to 2 HP, above 2 HP requires forced
     ventilation by external blower
Medium Voltage Variable Frequency Drives

Medium Voltage Reduced Voltage Starter

Duplex Pump Control with Lead-Lag, one to five float switch control

AC Motors

Surge Suppressors up to 6900 VAC

Two-speed Starters
   2 winding constant HP
   2 winding variable torque
   1 winding constant torque
   1 winding variable torque
   1 winding constant HP

Special applications:
Vertical Turbine Pumps in Connecticut and Rhode Island only, 
    application assistance, start-up and service will be provided
Loss of flow determined by loss of motor current
    to give protection from pump cavitation
Auto Restart after fault trip of across-the-line motor starters

Motor Control Centers (MCC)
    Replacement Motor Circuit Protectors and Starters
        in existing GE MCC.
    Ground Fault Protection components for installation in
        existing individual modules for GE MCC.
    Replacement of complete MCC Modules in existing GE MCC.
    New MCC by GE, Powell Industries or LS Industrial Systems    
DC Drives by GE

EMI/RFI Mitigation 
   Common  Mode Chokes
Replacement of controls or motors:
Wound Rotor Motor
Eddy Current Drives
Motor-Generator Set
NEMA C motor, high starting torque, normal slip
NEMA D motor, high starting torque, 5 to 13% slip,
Vari-Dyne ®, Vari-Drives ® US Electrical Motors
Synchronous motor with DC Excitation

Harmonic analysis is available in New York and New England


Motor Starters are our specialty for those control applications that are unusual.

Recent applications:

* Pump Protection - Undercurrent Protection to prevent cavitation with loss of fluid in the pump. Eliminates the need for low level sensing electrodes.

* Automatic Timed Restart of Across-the-Line electric motor starters to restart after under current trip, under voltage, over voltage, power loss, etc.

* Pump Pre-lubrication - solenoid valve opens reservoir to pour water into the pump impeller before start. The pump will refill the reservoir upon start in preparation for the next start.

* Field irrigation - Constant pressure regulation with variable frequency drives and a 4 to 20 ma pressure transducer input. Drives will operate independently of the field sprinkler system. Automatic high pressure shut down when too many sprinklers close, low pressure restart when sprinklers open.

* Undervoltage and Overvoltage Protection - Motors can operate at nameplate rating plus or minus 10%. Adjustable time delay on start is provided for voltage dips caused by motor inrush current.

* Type 3R or Type 4 Enclosure with Service Entrance Rated Fusible Disconnect and Lightning Arrestor.

* Variable Frequency Drives that may be placed in direct sun light with the addition of forced ventilation or air conditioning.

* Reduced Voltage Starters to interface with your existing Cla-val pressure reducing valve.

* Variable Frequency Drives will be interfaced with your facility controls.

Motor Control Products

Solid State Reduced Voltage Starters

Explosionproof Starters and Control


Wye Delta Reduced Voltage

Pressure Transducers

Motor Control - Many items are listed that are not in our store. You will also find additional notes on the products.

Pump Control Products

Simplex Starter Pump Control.

Duplex Pump Control.

Triplex Pump Control.

Domestic Variable Frequency Drive Pump Package.

Single Variable Frequency Drive Domestic Booster Pump Control.

Dual Variable Frequency Drive Domestic Pump Control.

Multi-motor Booster/VFD Pump Control.

Duplex VFD Chilled Water System Control.

Torque Control Soft-Starts

Power Quality Products

Automatic Tap Changing Transformers

Voltage Regulators

AC Line Reactors for Variable Frequency Drives up to 20 HP

Surge Suppressors

Ferrite Cores


Application Tips:

In 1952 the motor industry re-designed motors to reflect advancement in winding insulation. The new insulations could withstand higher temperatures and still give a nominal eighteen year lifetime.

The re-design allowed a smaller frame that gave less surface heat dissipation. Consequently, motors were designed to save raw material costs while allowing higher internal temperatures. Thus the "U-frame" was designed to replace the "original frame" motors.

In 1964 another re-design took place as insulation materials were designed to withstand even higher temperatures. Raw material costs were reduced as the smaller "T-frame" replaced the "U-frame."

Capabilities of the re-designed products also changed for the reason that the new re-designed motors were also optimized, i.e., the original frame motor could easily develop more horsepower than what the namplate was marked and the U-frame could develop only slightly more horsepower than nameplated. However, the T-frame motor was optimized so that it could develop no more than what the nameplate required. Thus, an original frame 10 horsepower motor might produce perhaps 12 horsepower, a 10 horsepower U-frame motor might produce 11 horsepower, but a 10 horsepower T-frame motor will produce 10.0 horsepower.


When machinery was designed using original frame motors, if the requirement was, for example, 11 horsepower, a 10 horsepower motor was used with the knowledge that the motor would perform adequately. When machinery was designed for use with a 10 horsepower U-frame and the horsepower requirement wad 10.5 horsepower, a 10 horsepower U-frame was used satisfactorily.

If either the original frame was replaced with a U-frame or a U-frame was replaced with a T-frame, the replacement motor might overheat and destroy itself while trying to handle the load.

Know thy motor! Measure and record running amps of all motors before they need replacement.

Select a replacement motor based on the measured running amps. If an older style motor needs to be replaced without the benefit of measured running amps, the general rule is to replace an original frame motor with a U-frame of the next higher horsepower rating and replace a U-frame with a T-frame of the next higher horsepower rating. In attempting to save energy by replacing a 10 horsepower original frame or U-frame motor with an energy saving motor, the question should be asked, "How efficient is my new, shiny, premium efficient, 10 horsepower T-frame motor when it burns up?"


When replacing the motor, if an existing sheave is worn then, if used again, it may damage the shaft of the new motor. You may want to replace the sheave also.

When replacing V-belts, use industrial belts rather than the automotive type. The difference is the angle of contact on the sides of the belts. An automotive belt will not have the proper lifetime if used on an industrial sheave.

When replacing belts that are used with a multiple groove sheave, always replace all the belts. If one new belt is used with one or more old belts then the new belt will wear or break before the others. The reason for that is that the old belts have been stretched and so the new belt will be doing all the work.


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Power Quality and Drives LLC
P.O. Box 83
Middlebury, CT  06762
Phone: (203) 217-2353
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