™
Frequently Asked Questions
1. What are the target applications for this line of disconnect
switches?
9. Are the disconnect switches operable by flange or side
handle?
Some of the applications that are ideal for this line of disconnect switches are
motor control panels, UPS, Food & Beverage, HVAC equipment, or any type of
electrical panel.
Most disconnect switches can be operated with a front, right side, flange or
direct mount handle mechanism, which increases flexibility for configuration at
the point of use and reduces the need for multiple parts in inventory.
2. What is the difference between UL 98, UL 489 and UL 508?
10.Do selector handles and pistol handles require different
shafts?
These different UL standards define the application for intended use. The
disconnect switches that are Listed UL 98 or UL 489 are for general purpose,
main disconnect, or branch circuit protection. The disconnect switches that
are Listed UL 508 are for motor disconnect applications.
3. Why are there two catalog numbers for some disconnect
switches with the same amperage and fuse type?
Some disconnect switches are available in both a compact and a standard
version with different footprint and SCCR. This allows flexibility and control
when designing panels.
4. Can the disconnect switches be used as a Service Entrance?
Yes, all UL 98 and UL 489 open disconnect switches can be used as a
Service Entrance. All requirements for a Service Entrance should be followed
during installations.
Yes, even though the shafts may have the same length and cross section, the
end that engages the handle is different for a selector handle and for a pistol
handle. A disconnect switch can be converted between selector and pistol
handle by replacing the shaft and handle.
11.Does it matter which orientation the disconnect switch is
installed?
Yes, standard 100-1200A non-fused disconnect switches [Catalog numbers
RD100-3-SCCR, RD200-_, RD400-_, RD600-_, RD800-_, RD1000-_ and
RD1200-_] may not be installed in a 90º counter-clockwise orientation (see
image below). They can be installed in a 0º, 90º or 180º clockwise orientation
(0º is when the text on the disconnect switch labels are right side up). All
other disconnect switches may be installed at 0º, 90º, 180º, or 270º.
The enclosed disconnects are not configured to be used as a Service Entrance.
5. Does this line of disconnect switches meet NFPA 79
requirements?
All fusible disconnect switches can be configured to meet NFPA 79
requirements for industrial machinery with the appropriate NFPA handle kit.
Please refer to the Cooper Bussmann Full Line Catalog to find the appropriate
kit.
6. What types of accessories are available for the disconnect
switches?
Easy to install modular accessories including front, right side and flange
operated handles, auxiliary contacts, finger-safe terminal shrouds, switched
4th poles and a variety of handle options make it simple to design the
disconnect switch for the desired application. All accessories are field installed
for open and enclosed disconnect switches.
Standard 100-1200A non-fused disconnect switches may not be
mounted in the 90º counter-clockwise orientation shown.
Disconnect switches may be installed in orientations other than vertically on a
wall, but require a derating factor Kp to be applied according to the figure
below.
7. Are the fusible disconnect switches double break?
Yes, double breaking is standard on this line of fused disconnect switches.
Both the lineside and the loadside of the fused disconnect switch are
disconnected when the switch is OFF. This helps ensure complete fuse
isolation and reduces hazards to personnel.
8. Can multiple padlocks be used with the rotary disconnect
switches?
Example: A 100A disconnect switch mounted horizontally from the ceiling
should be derated to 100A X 0.9 = 90A.
Yes, up to three ¼” diameter shank padlocks can be placed on all external
handles.
0413
BU-SB13417
Page 1 of 2
FAQ: 10075
™
Frequently Asked Questions
12.Can you install a fuse with an amp rating different than what
the fused disconnect switch is rated for?
16.What type of protection do the different NEMA ratings provide
for the enclosed disconnect switches?
Yes, you can install any fuse with the same case size up to the amperage
rating of the disconnect switch. Ex: A Class J 200A disconnect switch can use
any Class J fuse from 110A up to 200A.
For complete information about NEMA ratings and protection offered by each
NEMA type, please visit
http://www.nema.org/Products/Documents/nema-enclosure-types.pdf.
13.Can fuse reducers be used with the fused disconnect
switches?
17.Can parts from the current Bussmann line of rotary
disconnect switches be used with parts from a previous
Bussmann line?
Fuse reducers can be used on disconnect switches up to 100A [Catalog
numbers RDF60J-_, RDF60J-_-COMP and RD100J-_]. All other fused
disconnect switches do not allow for the use of fuse reducers.
14.Do fuses ship with the disconnect switches?
No, fuses must be ordered separately.
15.For enclosed disconnect switches, can the enclosure door be
opened when the disconnect switch is ON?
No, the handle interlock feature on all external front handles prevents the door
from being opened when the disconnect switch is in the ON position. However,
qualified personnel can override this feature with the use of a tool. All work
must be performed by a qualified electrician in accordance with OSHA
regulations and requirements of the latest edition of NFPA 70E. Proper PPE
must be worn when working on electrically energized systems.
No, parts from the current line and previous lines cannot be interchanged.
The complete assembly, including disconnect switch, shaft, handle and other
accessories must be from the same line.
18.What tools are available to transition the current Bussmann
line of disconnect switches?
There is an online cross-reference tool that provides the closest Bussmann
equivalent for competitive products as well as the previous Bussmann
offering. The cross reference tool can be found at:
http://www.cooperindustries.com/CrossRef.
19.Are the disconnect switches and accessories stocked
products?
Yes, the most common open and enclosed disconnect switches and
accessories are in stock and ship within 24 hours. Standard lead time for
non-stock enclosed disconnect switches up to 200A is two weeks. Contact
your local Bussmann Rep for all other standard times.
0413
BU-SB13417
Page 2 of 2
FAQ: 10075