Watlow SBL Card - Manual

SBL Card Data Sheet
1
General Description
The Watlow SBL card is a stand-alone control card
which accepts a proportional 4-20mA command
signal from a temperature control. It provides a
variable time-base, proportional output for a zero
cross-fired, DC input solid state relay (SSR). The
SBL can drive one SSR for single phase or two
SSRs for three-phase, two-leg applications. The
SBL is loop powered from the 4-20mA, so there is
no need for an external power supply. It easily
attaches to the SSR input terminals, making it a
compact power control with a variety of voltages and
amperages limited only by the SSR’s output.
Specifications
Dimensions
Bias Gain
- +
2.0"
(51 mm)
2.67"
(68 mm)
ON
SBL
08-5399
Setup Procedure
WSBL-XDSN Rev A00
January, 1996
Power Controls
Watlow Controls, 1241 Bundy Blvd.,
P.O. Box 5580, Winona, MN 55987-5580
Phone: 507/454-5300, Fax: 507/452-4507
SBL Card
1. Set the temperature control command signal to
20mA.
2. Adjust the Gain potentiometer until the SSR
output is just full ON (LED full on).
3. Set the temperature control command signal to
4mA.
4. Adjust the Bias potentiometer for ZERO output at
4mA (LED full off).
5. Repeat Steps 1 through 4 until no further
adjustment is required.
• Power Requirements: 4-20mA DC current.
Temperature controls must provide at least
7.5VDC (375
Ω
SBL input impedance).
• Linearity: Within ± 3% over a 20 to 80% power
region.
• Operating Temperature: 32 to 122°F/ 0 to 50°C
0 to 90% RH, non-condensing.
• Firing Mode: Variable Time Base @ 50% power,
3 cycles ON, 3 cycles OFF, zero-cross switching
with 1/2 cycle resolution.
• Output: 3.5VDC minimum. Current is dependent
upon the SSR input impedance.