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8
305C Series
Vishay Cera-Mite
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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
00
.2
Time In Seconds
.4
.6
.8
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
Time In Seconds
.6
.8
1.0
25
50
75
100
0
1.2
Cold
Start
3 Min.
Cooling
5 Min. Cooling