www.vishay.com

8

305C Series

Vishay Cera-Mite

ceramite.support@vishay.com

Document Number: 23086

Revision 14-May-02

PTCR Motor Start Packages

VISHAY CERA-MITE MOTOR START FEATURES

ADVANCED CERAMIC ENGINEERING FOR

HVAC

Vishay Cera-Mite’s capability in large diameter ceramic pellets,

unique formulations tailored to motor starting, and heavy duty

electrode systems, have been developed and proven with the

cooperation of HVAC industry experts over a period of 20 years.

INHERENT PERFORMANCE

Large diameter pellets make possible low resistance

start devices needed to match torque requirements of high

efficiency compressor motors.

Various package sizes offer selection of timing intervals,

providing optimum switching time without dependence on

sensing speed, counter EMF, or current.

RUGGED MECHANICAL CONSTRUCTION

Vishay Cera-Mite PTCR cases are molded from a UL94V0

high temperature, engineered plastic/glass composite.

Heavy duty aluminum contact plates and stainless steel

force springs are scaled to the pellet sizes and current

ratings to insure no internal arcing and to enhance quick

reset time.

Unbreakable metal mounting brackets attach securely with

a single screw. The NEW “U” - brackets developed by Vishay

Cera-Mite feature lower power consumption and greater reliability

by maximizing case to ground thermal impedance.

SIMPLE AND ECONOMICAL

A solid state device requiring only 2 quick connect wires

and one bracket screw to install. Compared to the alternative

start capacitor and relay, PTCR start devices save several

wires, occupy less panel space, mount more easily, and

cost less.

OUTSTANDING RELIABILITY

Over a fifteen year period, with an installed base of millions

of Vishay Cera-Mite PTCR start devices, experience has

demonstrated reliability at 1.0 FITS or less. Users have

benefited from very low warranty expense.

RESTART

CONSIDERATIONS

A properly sized PTCR will

provide adequate starting

current and starting time

with a cool down time of 3

to 5 minutes, coordinating

perfectly with standard “off

delay” equalization timers

Restart characteristics of

the three case sizes are

shown.

Fig T-13

Fig T-14

Fig T-15

25

% Initial

Current

CASE STYLE C

50

75

100

0

0

.2

.4

.6

.8

Time In Seconds

5 Min. Cooling

3 Min.

Cooling

Cold

Start

CASE STYLE B

0

.2

.4

.6

.8

Time In Seconds

1.0

5 Min. Cooling

3 Min.

Cooling

Cold

Start

25

50

75

100

0

CASE STYLE A

0

.2

.4

.6

.8

1.0

25

50

75

100

0

1.2

Cold

Start

3 Min.

Cooling

Time In Seconds

5 Min. Cooling