Specifications

NEW!
NETWORK & WIRELESS
840
NEW!
NETWORK & WIRELESS
13
WHEN YOU NEED IT RIGHT, RIGHT NOW, CALL KELE.
kele.com888-397-5353 USA
Building 1
Building 2
Building N
CPU
C
Main Processing EquipmentDistributed EMS/BAS Controllers
SP
C
SP
AC Power
*
SP
C
SP
AC Power
*
CPU
SP
*
SP
C
SP
AC Power
*
SP
C
SP
AC Power
*
SP
C
SP
AC Power
*
Data
Line
SP
C
SP
AC Power
*
SP
C
SP
AC Power
*
SP
C
SP
AC Power
*
*
Conductor from data line SP ground and AC power
SP ground to single point ground must be very short
SP
AC
Power
SP
Surge Protector
Model HSP-121BT1RU AC Power Surge Protector
Model PC642C Data Line Surge Protector
<
APPLYING SURGE PROTECTORS
Figure 2. Typical Installation of Equipment within a Small Area
• Ground wires to the suppressors are very short.
• An optional (depending on code) ground conductor connects
the ground bus to the main building power ground. This
conductor may be quite long, but that does not create a
problem now that the ground area has been established.
Protecting Multibuilding Data and Control Systems
The Protection Zone Concept can also be applied to
multibuilding, multidrop data and control systems. In Figure
3, the surge protectors located at the building entrance are
improperly positioned to protect the CPU and the controllers.
During lightning activity, ground potentials at opposite ends
of a building can be thousands of volts, causing damage to
electronic equipment. Also, surge protectors for data lines that
enter buildings have series resistance. The series resistance
of the surge protectors is additive. The total series resistance
often is too great and can cause communication or data line
problems. The installation in Figure 3 shows five protectors in
series over the length of the data line.
To properly configure surge protection on a multibuilding,
multidrop system (see Figure 4), connect the surge protector
on each controller drop so that the protector is not in series
with the main data line. When connected in this manner,
no more than two surge protectors are connected in series.
Using the Protection Zone Concept, locate the data line surge
protectors within the protection zone window along with an AC
service outlet surge protector for each respective controller.
Remember to keep the ground connections to the single point
ground very short.
SP
Data
Ground
Data Line
Surge Protector
Data Line
AC Power
Ground #2
Data Line
AC Power
Ground #1
Ground #3
AC Power
The Protection Zone
AC Outlet #1
AC Outlet #3
AC Outlet #2
March 2014
Building 1
CPU
SP
CC
Building 2
SP
C C
Data Line
C
SP
Building N
SP
C CC
SP
SP
CPU
C
Main Processing Equipment Distributed EMS/BAS ControllersSurge Protector
Summary
Remember the following when applying surge protection:
1. Keep all grounds inside the protection zone at the same
potential. If different ground potentials are present on
electronic equipment, damage will occur regardless of the
suppression used.
2. Protect all electrical and data circuits entering or leaving
the protection zone at the protection zone ground window.
Doing this keeps circuits at a safe voltage with respect to the
ground window. This safe voltage is the clamp voltage (let-
through voltage) of the respective suppressors.
The majority of surge protection installations are fairly simple
and only involve bonding suppressor grounds to AC service
grounds at the ground window. Existing sites may involve
some rewiring to accomplish the best results. In order to keep
the data line surge suppressor ground and AC service ground
wires very short, wiring must sometimes be moved. When
applying surge protectors, using the Protection Zone Concept
will effectively protect EMS and BAS installations.
Figure 3. Improper Positioning of Surge Protectors
Figure 4. Proper Positioning of Surge Protectors