PTC305C Series www.vishay.com Vishay Cera-Mite PTC Thermistors Motor Start Packages FEATURES Large diameter ceramic pellets for high starting current Various package sizes for optimum inrush current and switching time Rugged mechanical construction for reliable long life operation UL approved packages Plastic case mold UL 94 V-0 approved Adapted accessories for easy mounting Material categorization: for definitions of compliance please see www.vishay.com/doc 99912 QUICK REFERENCE DATA PARAMETER VALUE UNIT APPLICATIONS Resistance value at 25 C 15 to 75 Single phase motor start assist in Tolerance on resistance value 30 % - Refrigerator systems Maximum current ratings 6 to 36 A RMS - Air-conditioning systems Switching temperature 110 to 120 C - Heat-pumps Switching times (typical) 0.25 to 1.0 s - Small compressors Maximum voltage rating 410, 500 V RMS Operating temperature range -10 to +80 C Storage temperature range -25 to +105 C PTC MOTOR START SELECTION CHART MAX. SWITCH CURRENT COMPRESSOR COMPRESSOR VISHAY CERA-MITE CASE R () R ( ) VOLTAGE DYN 25 TIME RATING RANGE RANGE PART NUMBER STYLE 20 % 30 % RATING t (s) at 230 V (A ) (BTU 000) (HP) RMS (V ) RMS PTC305C20 C 25 35 0.25 10 410 10 to 28 0.75 to 2.0 PTC305C21 C 35 50 0.35 8 410 8 to 18 0.5 to 1.5 PTC305C22 C 50 75 0.50 6 410 5 to 12 0.25 to 1.0 PTC305C19 B 20 30 0.50 18 500 20 to 50 1.5 to 4.0 PTC305C12 B 25 40 0.60 15 500 18 to 42 1.5 to 3.5 PTC305C2 B 50 85 1.00 12 500 10 to 25 1.0 to 2.5 PTC305C9 A 10 15 0.50 36 500 28 to 68 3.0 to 7.0 PTC305C11 A 12.5 20 0.60 30 500 28 to 62 3.0 to 6.0 PTC305C1 A 25 42.5 1.00 24 500 14 to 36 1.5 to 3.5 PTC MOTOR START ACCESSORY SELECTION CHART ACCESSORY DESCRIPTION PART NUMBER PTCAUX36-520M Round mounting bracket for case style C PTCAUX36-520H Round mounting bracket for case style A and B PTCAUX7-36-5C U-shaped mounting bracket for case style B PTCAUX7-36-4C U-shaped mounting bracket for case style A PTCAUX50-1278 Jumper wire for case style A Revision: 11-Sep-15 Document Number: 23086 1 For technical questions, contact: ceramitesupport vishay.com THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc 91000 PTC305C Series www.vishay.com Vishay Cera-Mite ECONOMICAL SOLID STATE TORQUE ASSIST FOR HEAT PUMPS, ROOM AIR, COMMERCIAL AND RESIDENTIAL AIR CONDITIONING AND REFRIGERATION SYSTEMS Positive Temperature Coefficient Themistors (PTC) have Safety Agency Recognition been used for many years in millions of HVAC applications Vishay Cera-Mite motor start PTC thermistors are to provide starting torque assistance to Permanent Split recognized by Underwriter Laboratories file E97640 in Capacitor (PSC) single phase compressor motors. accordance with standard for controllers and refrigeration Sizes are available to cover the full range of 120 V/240 V components UL 873 or UL 60730 and Canadian Standard PSC compressor motors. C22.2 No. 24. All packages and accessories are RoHS-compliant. RELATIVE COMPARISON OF VARIOUS MOTOR STARTING METHODS Three methods have historically been employed to generate The importance of each category is dependent upon the motor application and industry sector. starting torque for PSC motors. All are well-proven technologies and may be compared relative to one another In general, if the PTC starter produces sufficient starting based upon categories shown below. torque, it is considered the simplest and most economical choice. Table 1 MECHANICAL ELECTRICAL FINANCIAL SENSITIVE STARTING EASE PANEL ACCELERATION ACCELERATION RESET INVENTORY TO EMI/RFI PURCHASED METHOD OF SPACE TORQUE (SWITCH) TIME TECHNOLOGY MIX RELIABILITY MOUNTING GENERATED COST WIRING REQUIRED PRODUCED TIME REQUIRED REQUIRED DIRECTION Simple 3 min to PTC starter Lowest No Lowest Fixed No Solid State Lowest Highest Lowest 2 wire 5 min Start cap Moderate with PTC 2 min to 2 wire or Medium Yes Medium Fixed No Solid State Medium Medium Medium acting as a 5 min 3 wire current relay Start cap Difficult Variable used with Electro 4 wire or Highest Yes Highest based on None Yes Highest Lowest Highest potential or Mechanical 5 wire motor speed current relay SIMPLIFIED PTC STARTING DIAGRAM Start Sequence Restart When starting the compressor, contactor (M) closes the It is important to provide time between motor starts to allow PTC, which is at low resistance, provides starting current to the PTC to cool to near its initial temperature. This time is the motors auxiliary winding. After time delay (t), the current usually 3 min to 5 min and is determined by the thermostat passing through the PTC causes it to heat and switch to a (THERM) or separate time-delay relay (TR). Attempts to very high resistance. At this point the motor is up to speed restart in less time may be successful depending on and the run capacitor (C ) determines the current in the compressor equalization, line voltage, temperature, and R auxiliary winding. The PTC remains hot and at high other conditions. If the motor were to stall in a locked-rotor resistance as long as voltage remains on the circuit. When state, overload device (PD or TS) would open the line and a contactor (M) opens, shutting off voltage to the compressor, further time delay would occur until the motor overload is the PTC cools to its initial low resistance and is again ready reset. Motor start PTCs are applied to compressors having to provide torque assist on the next startup. means to equalize pressure during shutdown. TYPICAL PTC CHARACTERISTICS Fig T-2 AS A MOTOR START DEVICE L PD 1 M Fig T-3 PSC Protective T TS HERM MOTOR Device CURRENT 10 000 10.0 Internal MAIN Motor TR Winding M Overtemp AC Line 1000 1.0 Switch Optional OFF 120 or 240 Time Delay TR C VOLTS AC R AUX. Relay M 100 Switch Time (t) 0.1 Protective PTC RESISTANCE Device M L 2 Low Voltage Control Transformers Not Shown 10 0.01 50 100 150 PTC Temperature C Revision: 11-Sep-15 Document Number: 23086 2 For technical questions, contact: ceramitesupport vishay.com THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc 91000 PTC Resistance () PTC Current (A ) RMS