PTC Motor Temperature Protection Guide: Delta C2000/CP2000 VFD (EN)

PTC FUNCTION for Delta C2000 and CP2000 CONTENTS: 1 GENERAL ..................................................................................... 2 1.1 PTC for motor temperature protection ........................................................................................ 2 1.2 Standards .................................................................................................................................... 2 1.3 Motor layout ................................................................................................................................

2 1.4 PTC characteristic ....................................................................................................................... 2 1.4.1 Definitions .................................................................................................................................................................... 3 1.4.2 PTC curve .................................................................................................................................................................... 3 1.4.3 PTC switching level ......................................................................................................................................................

3 1.4.4 PTC input ..................................................................................................................................................................... 3 2 C2000/CP2000 PARAMETERS AND WIRING .................................... 4 2.1 PTC wiring and connection ......................................................................................................... 4 2.1.1 Recommendations and limitations ................................................................................................................................ 4 2.2 Parameters for PTC-function: Pr06.29 Pr06.30 and Pr03-00, Pr03-15 ...................................

4 3 DIMENSIONING ............................................................................. 5 3.1 Connection diagram .................................................................................................................... 5 3.2 General formula .......................................................................................................................... 5 3.3 Dimensioning R 1 .........................................................................................................................

5 3.3.1 Conditions for R 1 .......................................................................................................................................................... 5 3.3.2 R 1 value ....................................................................................................................................................................... 6 3.3.3 Conditions for PTC Level .............................................................................................................................................

6 3.3.4 PTC Level Pr06-30....................................................................................................................................................... 7 3.4 Reset ........................................................................................................................................... 7 3.5 Summary ..................................................................................................................................... 7 3.5.1 Circuit & wiring .............................................................................................................................................................

7 3.5.2 Parameter settings ....................................................................................................................................................... 8 4 CLIXON ........................................................................................ 9 4.1.1 Wiring for and connection of clixon ............................................................................................................................... 9 4.1.2 Parameter settings ....................................................................................................................................................... 9 Arnoud de Bok 21 January 2014 1

Стр. 1

1 GENERAL 1.1 PTC for motor temperature protection To protect motors from overheating, PTCs (also called thermistors) are incorporated in the motor windings. At the pre-defined temperature the PTC’s resistance suddenly increases. This can be measured. Especially when motors are used for long periods of time at low speeds, the cooling could be insufficient. In that case the motor can be equipped with optional PTCs (ask the motor manufacturer). 1.2 Standards PTCs for motor protection are manufactured acc. to the standards DIN44081 (for single PTCs) and DIN44082 (for 3 PTCs in series).

1.3 Motor layout A typical layout of the PTCs in a motor is as follows, whereby the 3 PTCs are connected in series. (In case of 6 PTCs in series, each winding incorporates 2 PTCs in series.) 1.4 PTC characteristic The characteristics of 1, 3 or 6 PTCs is shown below. 6 PTCs Resistance in Ω 3 PTCs 1 PTC Temperature in ° C 2

Стр. 2

1.4.1 Definitions NAT Normal Excitation Temperature (German abbreviation) PTCs are manufactured to switch at a certain temperature, called “NAT”. 1.4.2 PTC curve The PTC curve for a single PTC is defined as follows: 1.4.3 PTC switching level 1 PTC switches between [NAT+5 ° C] and [NAT+15 ° C] 3 PTCs in series switch between [NAT-5 ° C] and [NAT+5 ° C] 6 PTCs in series switch between [NAT-20 ° C] and [NAT] As a user of AC Motor Drives, you don’t have to worry about the value of NAT, this has been taken care of by the motor manufacturer. The standardisation of PTCs ensures they switch at pre-defined resistance levels. 1.4.4 PTC input A PTC-input should have the following functionality:

R PTC Ω : may not switch 1650 Ω PTC Ω : switch R PTC >4000 Ω : must have switched 3 Temperature range Resistance Measuring voltage -20°C to NAT-20°C ≤250Ω 2.5V NAT-5°C ≤550Ω 2.5V NAT+5°C ≥1330Ω 2.5V NAT+15°C ≥4000Ω 7.5V

Стр. 3

2 C2000/CP2000 PARAMETERS AND WIRING Via a number of parameters the VFD-C and VFD-CP offer full flexibility to set the Motor PTC Overheat Protection Level and the action when the protection level is reached. Refer to the VFD-C and VFD-CP User Manuals for an extensive description of the parameters. 2.1 PTC wiring and connection The PTC is connected to the AVI input as follows. Note: When used for PTC, the AVI input cannot be used for frequency command. Note: For AUI and ACI, both in 0-10V, the procedure is the same. resistor-divider R1 PTC R1 1 20k Ω U +10V 10.4 11.2V AVI impedance 20k Ω 2.1.1 Recommendations and limitations 2.2 Parameters for PTC-function:

Pr06.29 Pr06.30 and Pr03-00, Pr03-15 For extensive description of the parameters, please refer to the User Manual, Chapter 12. 4 C2000V/CFDP-E2000 +10V AVI 4207kkΩΩ ACM internal circuit Parameter Description Range/Setting Unit Default 06-29 PTC Overheat treatment Sets the action when the PTC Overheat Warning Level (P06.30) is reached. 0=Warn and keep running 1=Warn and ramp to stop 2=Warn and coast to stop 3=No warning 0 06-30 PTC Level Sets the Alarm Level. The VFD-C displays blinking [PtC2]. Action acc. to P06.30. 0.0∼100.0% 0.1% 50.0% 03-00 AVI function Selects the AVI function. Set 6 to select PTC input. 0∼17 n.a 1 03-15 AVI Filter Time Selects the AVI filter time (in noisy environment).

0.00∼20.00 0.01s 0.01

Стр. 4