Start Capacitors

Motor Start Capacitor

Electrolytic capacitors are employed in single phase induction motors in order to increase their starting torque.

It is necessary that such starting takes place in a fraction of a second and that once starting has occurred the capacitor is disconnected from the circuit by means of either a starting switch or relay.

The capacitive element is made of aluminium foils treated and separated by a leaf of impregnated paper as the electrolyte.

Cases are molded in a thermo setting material and terminals are 6.3mm Faston type.

Start Capacitor General Characteristics

Applications :   For A.C. Use. Starting of single phase motors.
Construction :   Etched aluminium foil.
Protection :   Moulded thermosetting plastic case. Sealing by rubber disk and bakelized paper. Safety Valve.
Terminals :   6.3 mm double 'Faston' type.
Mounts :   Via clips.

Start Capacitor Technical Characteristics

Reference Standards : VDE 560-8 : ASE 1029 : IMQ-CE1 33-3
Temperature : Operating Range: Lower Limit = - 25°C
Upper Limit = + 65°C
Capacitance Tolerance : 0 + 25%
Rated Voltage : 220/275 volts
Working Frequency Range : 50/60 HZ
Dissipation Factor : Average = 6%
Maximum = 10%
Duty Cycle : 3'/1.7% Hour Applications N = 20
Application Time
t = 3 seconds , Nxt = 60
i.e. 20 Starts per hour, 3 secs application time.
Extension of Duty Cycle : These capacitors withstand heavier duty cycles than the rated one. The table shows the maximum Nxt value (number of hour applications multiplied by application time) and the maximum admitted application time T max.
For temperatures below 55°C, the product Nxt and T max, can be multiplied by the following factors.
Ambient Temparature Factor : 55°C 45°C 35°C 25°C 15°C
1 1.25 1.5 1.75 2