Rt. 29 Scott Depot WV 25560-0070
Model 18TBP/TB controls provide infi-
nitely variable control of single-phase
a.c. voltage to resistive heating ele-
ments. These controls are solid-state
replacements for variable transformers,
mercury relays, saturable core reac-
tors, and electromechanical contactors.
Power Triacs replace contacts and
brushes to control electric power with-
out moving parts, and, when operated
within their stated ratings for current,
voltage, and temperature, have no
known MTBF or life expectancy rating.
Description:Variable-Voltage
Power Control
Product Range:120-240 VAC,
5-25 amps.
Application: R esistance Loads
All Solid-State Construction
Short Circuit Protection
Integral Heatsink Chassis
No Thermal Derating
Replace Variable Transformers
Electric Heater Control
Light Dimming
Hot-Wire Cutting
Heat Sealing and Packaging
Plastic Molding and Extruding
Food Preparation Equipment
TYPICAL APPLICATIONS
Model 18TBP/TB
FEATURES
Model 18TBP controls are compact,
lightweight packages that employ
single hole mounting to panels and
enclosure doors. Model 18TB con-
trols are designed for rear or rack
mounting. Both utilize an electrically
isolated heatsink chassis.
Model 18TBP/TB controls incorpo-
rate exclusive design features to
protect power semiconductor com-
ponents against damage. “2 milli-
second” fuses protect against
short-circuit damage; an R-C snub-
ber network protects against dv/dt
failure; an integral heatsink chassis
allows continuous operation in
ambients to 50
Power Circuit: p ower Triac with par-
allel R-C circuit for dv/dt protection
and current-clamping 2 millisecond
fuse for short-circuit protection.
Control Circuit:R-C network with
variable-resistance potentiometer
adjusts firing capacitor into bilateral
diode connected to power Triac gate
for stable, full-range control.
Mains Frequency: 5 0/60 Hz.
Output Voltage:0-95% of input.
Overall Efficiency: 99%.
Power Loss: approximately 1.5
watts/amp.
Voltage Drop Across Power Circuit
at 100% Output: 1-2 volts maxi-
mum/phase.
Control Input:manual control via
variable potentiometer.
Control Power: 1 watt.
Fuse Protection:2 millisecond I
fuses are factory tested and coordi-
nated with all power semiconduc-
tors, considering:
PANEL- OR CHASSIS-MOUNT
Three Pillars Of Protection
EXCLUSIVE ADVANCED
SPECIFICATIONS
TECHNOLOGY:
o
C with no derating.
2
t
APPLICATION ASSISTANCE - 304/757-7354
Ambient Temperature Range: -10 to
+50
Terminal Connections: B akelite or
thermoplastic blocks.
Model 18TBP/TB controls are rated
for use with constant resistance
loads. Size units by actual load cur-
rent, not kW.
1> Always use maximum possible
load current for sizing purposes.
2> The amp rating is determined by
the fuse. Current draw must not ex-
ceed the fuse rating at any time.
3> Rated voltage of connected load
should match control input voltage.
Application: s ingle-phase, 800 watt
nichrome heating element; input
voltage 120 VAC, 60 Hz.
Model Number Selection:
a. Triac-based variable-voltage: SC
b. Panel-mount: E
c. 120 VAC input: 12
d. Amp rating, calculated as follows:
800 = 6.66 amps
120
Since 6.66<10, amp rating: -10
Model Number:SCE12-10.
PERFORMANCE NOTE: Triac
power circuits may “slave” when
multiple units are used on 240 VAC
lines derived from three phase
mains. For optimum performance,
use on single phase, 240 VAC de-
rived from 3-wire, 120/240 VAC
mains.
WHEN ORDERING, SPECIFY:
SIZING CONSIDERATIONS
a. fuse element melt time t
b. peak melt current I
c. arc quench time t
d. peak arc current I
Model Number
Input Voltage
Load Specifications
o
C.
SCR Power Controls
SIZING EXAMPLE
24 HOUR FAX - 304/757-7305
Model 18TBP/TB
arc
arc
melt
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.
;
melt
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