Allen-Bradley 1391B Series, Instruction Manual

Page: 60 / 82

Transformers and Shunt Regulators
Chapter 9
9-58
Table 9.B shows the nominal resistor power trip levels in watts for the
various switch settings. When shunt requirements exceed the selector
setting, the excess power will cause the bus voltage to rise, resulting in an
overvoltage fault condition.
Table 9.B
Nominal Power Trip Level Reference Data (continuous watts,
±
10%)*
SW1
Switch
Setting
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
15A
W/ Int. 16
Ohm Resis-
tor
67
71
75
80
85
91
99
107
118
130
145
164*
189
223
272
347
22.5A
W/ Int. 12
Ohm Resis-
tor
73
77
82
86
92
98
105
113
122
133
146
162*
183
208
242
290
22.5A
W/ Ext. 9
Ohm Resis-
tor
98
103
109
115
122
130
139
150
163
177
195
216
243
277
323
386*
45A
W/ Ext. 5
Ohm Resis-
tor
215
227
241
256
274
294
317
344
378
417
466
527
607
715*
872
1115
* Denotes the maximum allowable settings for factory supplied configurations.
ATTENTION: To guard against personal injury and/or
equipment damage from an overheated resistor, the designated
duty cycle settings for factory supplied shunt resistor
configurations must not be exceeded. Check the Duty Cycle
Selector Switch (SW1) to ensure that it is set properly before
operation.
ATTENTION: When using a customer supplied external shunt
resistor assembly, the Duty Cycle Selector Switch (SW1) must
be set to an appropriate level for that resistor assembly. Consult
the resistor manufacturer for the appropriate derating
guidelines. Failure to comply could result in personal injury
and/or equipment damage from an overheated resistor.
!
!