Siemens 21-115532-001 ユーザーズマニュアル

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INTRODUCTION  
 
Page 5 
PROTECTIVE MEASURES 
Bypass Arrester. All JFR regulators are equipped with a 
properly sized arrester, connected externally between the 'S' 
and 'L' line terminals. The arrester is provided to protect the 
series winding of the regulator from line surges. By itself, the 
bypass arrester does not provide lightning protection for the 
regulator. 
Lightning Protection. The number of lightning arresters used 
will be a discretionary decision on the part of the user, 
considering such factors as isokeraunic level and degree of 
risk of damage to be accepted. The minimum recommended 
lightning protection consists of a properly sized arrester 
between the 'S' or 'L' bushing and ground on a single phase 
or a wye connected system. A delta connection system 
requires the use of two arresters to accomplish minimum 
protection levels. Additional protection can be obtained with 
the use of arresters at both the 'S' and 'L' terminals in single 
phase or wye systems and on all three terminals on a delta 
system. 
For best results, install lightning arresters on the mounting 
lugs adjacent to the bushings near the top of the tank. The 
lugs are 0.5 - 13NC located on 2.5 inch centers. Ground the 
arrester(s) and the regulator tank solidly to the same ground 
connection. Be careful to keep the ground lead connections 
as short as possible. 
Thru Fault. Type JFR regulators are rated under condition of 
thru-faults per ANSI C57.15. 
The user is advised to provide for additional source imped-
ance, bus sectionalizing or other means of limiting the avail-
able thru-fault current if these criteria are exceeded at the 
installation. 
 
CONTROL CONNECTIONS 
Many regulators can be used at several different nominal 
system voltages. It is therefore necessary to assure that the 
regulator is properly connected at the 19 pin upper terminal 
block for the system voltage on which the particular regulator 
will be used. 
 
Figure 5A 
For this purpose, it is necessary to use the nameplate 
drawing and control diagram found in the control enclosure. 
1.  Refer to the Nameplate. The P2 column indicates the 
correct connection for lead P2 based on the system 
voltage. Using the applicable control diagram, the 
terminal designation of the nameplate can be cross 
referenced to the proper terminal on the 19-pin terminal 
block. 
2.  Depending on the regulator, there may be a second 
nameplate column indicating that lead U2 should also be 
connected.   If so, the U2 column indicates the correct 
connection for lead U2 based on the system voltage 
Using the applicable control diagram, the “U” terminal 
designation of the nameplate can be cross referenced to 
the proper terminal on the 19-pin terminal block. 
3.  For regulator equipped with fans for forced-air cooling, 
another set of connections will be shown. 
 
NOTE
  Matters specifically relating to the Accu/Stat
TM
 
control used in conjunction with the regulator are 
not included in this manual. Refer to the 
appropriate control instruction manual.