Banner SMI30 Series—Intrinsically Safe - Manual (Page 2)

Intrinsic safety barriers are available from Banner. Current trip point amplifier CI3RC2 is also offered. Several mounting brackets are
available.
SMI30 Series receivers have a red LED alignment indicator that lights whenever the receiver "sees" its modulated light source. Emitters
have a red LED to indicate "power on". All LED indicators are mounted internally to preserve the waterproof integrity of the sensor hous-
ing, and are visible from both the side and front of the sensor through the sensor's quad-ring sealed acrylic lens.
The innovative circuitry used in SMI30 Series emitters and receivers provides the best noise immunity of any self-contained opposed
mode sensor pair. For applications where optical crosstalk between sensors might be a problem, SMI30 Series emitters and receivers
are available with a choice of three modulation frequencies (frequency "A", frequency "B", or frequency "C"). This makes it possible to
use high-powered sensor pairs of different frequencies in close proximity to each other without crosstalk. (NOTE: frequency "A" is stand-
ard; frequencies "B" and "C" are available by special order. An emitter and its receiver must be of the same modulation frequency.) See
the models table for a summary of models.
Each unit is supplied with two hexagonal jam nuts. A 30 mm clearance hole is required for mounting, and mounting bracket models
SMB30MM, SMB30S, and SMB30C are available. All models have a built-in standard quick-disconnect ("QD") connector. "QD" models
mate with 12-foot long model SMICC-312 or 30-foot long model SMICC-330 mini-type QD cable (sold separately from sensor).
Design Standards
ATEX (European) EN 60079-0, EN 60079-11, EN 60079-26
Canadian CAN/CSA C22.2 No. 0-M91, No. 142-M1987, No.157-92, No. 1010.1, E60079-0, E60079-11
United States FM Class 3600, 3610, and 3810, ANSI/ISA 61010-1 (82.02.01), ANSI/ISA 60079-0, 60079-11, and 60079-26
Wiring Information
SMI30 Series sensors are certified intrinsically safe ONLY when used with certified energy-limiting intrinsically safe barriers. Emitter units
use a two-wire hookup (there is no output connection). Note from the wiring/hookup diagram that the receiver installation may be made
using either a single barrier (2-wire hookup) or with a dual channel barrier (3-wire hookup). In the 2-wire configuration, the sensor acts as
a current sink, drawing less than 10 mA in the OFF state and more than 20 mA in the ON state. The customer must provide a current
sensing device ("current sensor" in the diagram) to convert the current to a logic level. SMI30 Series sensors may be used with Banner
Current Amplifier Control Module CI3RC2.
The CI3RC2 module may be purchased (with model RS-11 module socket, one dual-channel barrier, and DIN rail barrier mounts inclu-
ded) by specifying kit model CI2BK-2. One dual-channel intrinsic barrier (alone) may be ordered by specifying model CI2B-1. See
Acces-
sories on page 6.
In the 3-wire configuration, the output may be used directly to control loads of less than 15 mA.
In selecting the barrier, it is important to consider the barrier's resistance. The sensors must have at least 10 volts across the brown and
blue power leads for proper operation, and the barrier will cause a voltage drop due to its resistance. The formula that determines how
much resistance is allowed is: R = 40 (supply voltage – 10 volts).
If the supply voltage is 24V dc, then the maximum resistance is 560 ohms. If the supply voltage is 18V dc, then the maximum resistance
is 320 ohms. This includes the resistance of any current sensing device used (in the 2-wire configuration), so the barrier resistance must
be further reduced by the current sensor resistance.
Note that, in the 3-wire hookup, the barrier is in series with the load. This results in an apparent saturation voltage of the output that is
higher than the sensor output by the amount of IxR (current times voltage) drop through the barrier.
Emitters use the 2-wire hookup; receivers use either 2- or 3-wire hookup. Review to the models table for a summary of models.
Barriers are generally classified as either "positive input" or "negative input". SMI30 Series intrinsically safe sensors require "positive
input" barriers for both supply and load. The blue (negative supply) lead of the sensor is normally connected to the ground terminal of the
barrier.
The user of this equipment is responsible for proper installation and maintenance of the equipment, and must conform with the certifica-
tion requirements relating to barriers and to maximum allowable capacitance and inductance of the field wiring. If you are in doubt about
these requirements, our applications engineers can refer you to the appropriate authority.
SMI30 Series Intrinsically Safe Sensors
2 www.bannerengineering.com - tel: 763-544-3164 P/N 035331 Rev. E