Watlow VPAC-BT Remote Mount Transformer - Manual

General Description
The BT card (Watlow P/N 08-5406) is time proportioning
with a variable (very fast) time base. At 50% power, one
full cycle is ON, and one full cycle is OFF. At 25%
power, it is ON one cycle and OFF for three. At 90%, it
is ON nine cycles and OFF for one. As the command
signal gets farther from 50% power, the time base gets
longer. The maximum time base resolution is 1 in 360
ac cycles. The BT card is factory set for 4-20mA into
250
Ω
. It can be changed to a voltage input by removing
the 300
Ω
, R22 resistor, located on the lower right corner
of the card. Without R22, it is a 5K input impedance.
See the illustration on the reverse side. Bias and gain
pots allow the card to be adjusted for any voltage from
0-3V
Î (dc) to 15V Î (dc) or current between 0 to 25mA.
BT card power supply requirements are 24V Å (ac) cen-
ter tap transformer secondary. Transformer primary
must be connected to the same line phase as the heater
load. For example, is the heater is powered by L1 and
L2, then the power transformer must also be connected
to L1 and L2. See the illustration on the reverse side.
Dimensions
Specifications
(1276)
Input
•
Process input factory set @ 4-20mA Î (dc)
• Input impedance 250
Ω
(clip resistor for 5K
Ω
voltage
input), or manual control input
Output
•
Burst firing control, variable time base
• TTL compatible (5V logic) at about 5mA @ 5V. Will
drive one industry standard 3-32V
Î (dc) input ran-
dom fire SSR. For single phase only.
Line Voltage Power
•
50/60 Hz V~ (ac) line frequency
• Voltage ±10%, 120, 208, 240, 277, 380, 415, 480V~
(ac). Power transformer is supplied with the BT
card. When ordering, specify power supply voltage
and line frequency.
Line Voltage Compensation
•
10%
∆
in line, 2%
∆
in load in the 30% to 70% power
region.
Input to Output Linearity
•
2%, 30% to 70% power region
Operating Environment
•
32 to 122°F (0 to 50°C)
Storage Temperature
•
-40 to 185°F (-40 to 85°C)
Options
•
Manual control kit for voltage input cards (1K
Ω
potentiometer) #08-5362. Includes dial, knob, 1K
Ω
pot and wiring.
Ordering Information
•
Watlow P/N 08-5406
2.5"
(64 mm)
2.5"
(64 mm)
3.0"
(76 mm)
Input
+ _
Bias Gain
To V Î (dc)
Input SSR
08-5406
R22 Watlow Controls
1241 Bundy Blvd., P.O. Box 5580
Winona, MN 55987-5580
Phone: 507-454-5300, Fax: 507-452-4507
VPAC-BT
Remote Mount Transformer
Data Sheet
0600-0028-0002 Rev C (1277) Made in the U.S.A.
January, 1998 Printed on Recycled Paper
10% Postconsumer Waste