Bray 52 Series - Manual (Page 8)

BRAY Series 52 Valve Status Monitor
Operation and Maintenance Manual
6
This drop in voltage becomes paramount when
connecting several valve status monitors in series,
each unit will have a voltage drop across it – add-
ing each subsequent drop and subtracting from
the supply voltage yields the resulting voltage at
the end of the series connection. The user needs
to ensure that the supply voltage is large enough
so that the resulting voltage after all the drops is
above the min. operating voltage of the last S52 in
the series connection. Sensors located a great dis-
tance from the load require consideration as well,
as a general rule, every 1000 ft. of wire will have
a resistance of 10Ω (see electrical code references
for the resistance value of specific wire sizes), it is
important for the customer to ensure that the dis-
tance between the S52 and the control panel is not
long enough to cause the voltage drop to fall be-
low the minimum operating voltage of the sensor.
Residual current is often referred to as leak-
age current. In the “Off” state (target is NOT in
proximity of the sensor) the sensor draws a small
amount of current in order to power the device’s
electronics. This is necessary for the device to
sense the target at any point in time when the sup-
ply voltage is applied. It is important that this
residual current is below the maximum Off-State
current rating of the control system.
Target Mounting
All configurations of the S52 are offered with two
types of targets; adjustable and non-adjustable.
Standard S52 (AC, DC, and DC Intrinsically Safe
units) utilize inductive proximity sensing technolo-
gy to provide valve position indication; the fieldbus
capable versions utilize hall effect sensing technol-
ogy to accomplish the same objective. When ap-
plying fieldbus capable S52s, the same targets are
used; however, small magnets are located in the
small chambers behind the metal inserts on the
sides of the targets.
Figure 1: Adjustable Target Kit. From
Left to Right: (1) S52 Mounting Screws,
(2) Base, (3) Middle Piece, (4) Top, (5)
Yellow Pointer w/ mounting screw
Figure 2: High visibility indicator with adjustable
target. Pictured from left to right:
(1) Indicator cover w/mounting screws, (2) indica-
tor w/mounting screw, and (3) adjustable target.
Adjustable Target Mounting
The adjustable versions are for customers that want the flexibility to position their indication limits outside
of the standard 0 to 90°. The components that come in the adjustable target kit are displayed in Figure 1.
Figure 2 shows the components of the High Visibility Indicator Kit and the adjustable target kit.