10250T3 EATON CUTLER HAMMER, 10250T3 Datasheet - Page 233

• Manufacturer Part Number: 10250T3
• Description: CONTACT BLOCK, 2NC, 6A, SCREW
• Manufacturer: EATON CUTLER HAMMER

Specifications of 10250T3

• No. Of Poles: 2
• Contact Current Max: 6A
• Contact Voltage Ac Max: 600V
• Contact Voltage Dc Max: 250V
• Switch Terminals: Screw
• For Use With: 10250T Series Pushbuttons And Indicating Lights
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

March 2008
Selector Switch Selection
Cam and Contact Block Selection
Selector switches in their varied forms
(2-position, 3-position, and 4-position)
are a big factor contributing to the
great flexibility of control that a well
rounded line of “pushbuttons” can
achieve. Because of their flexibility, they
tend to cause difficulty with product
selection and application. The following
systematic approach should simplify
that task.
Cam and contact block selection is
better understood if you:
■
■
■
■
Figure 47-147. Contact Circuit Locations
CA08102001E
Work with each incoming and out-
going wire/circuit separately.
Recognize the terms NO and NC
only identify the type of contact by
its mode before mounting to the
operator. The “X-O” table (Page 47-
234) shows how that contact will act
after assembly to the operator with
the selected cam shape.
X = closed circuit, O = open circuit.
One NO-NC contact block may be
mounted behind each plunger of the
mounting adapter for a total of four
circuits.
Each cam has two separate lobes,
each of which operates one of the
two contact block plungers indepen-
dently of each other. Those are
identified as position 1 (locating nib
side) and position 2 (opposite of
locating nib). The position designa-
tions give direction in selecting and
mounting of the contact blocks (see
Figure 47-147).
10250T
Locating Nib
1
E34
2
Systematic Approach
Application: HAND-OFF-AUTO Selector
Switch. In this circuit, one incoming
line is distributed to two other outgoing
circuits by the switch. The two circuits
can be looked at individually.
Step 1: Elementary Diagram.
Construct on paper, or in your mind, a
simple elementary diagram of the
switching scheme as follows:
Step 2: “X-O” Pattern.
From the elementary diagram, you can
construct an “X-O” diagram which
describes when the contacts are to be
closed (X) or open (O) in the various
positions of the switch. The “X-O” for
the HAND circuit looks like this:
In this circuit, you want a contact
closed on the left (HAND) but open in
the center and right.
For the AUTO circuit, the “X-O” diagram
would look like this:
Putting them together, the complete
“X-O” diagram is:
Once the “X-O” diagram has been
generated, the next step is to select the
cam and contact block, or blocks,
needed to perform the desired “X-O”
functions. The selection table on the
following page lists the various types
(shapes) of cams by number to choose
from and the type of contact and posi-
tion to achieve the function outlined in
your “X-O” diagram.
Step 3: Cam Selection.
The cam you select determines the
operation of all contact blocks mounted
to the operator. It is selected on the
basis that it provides the simplest cir-
cuitry for the desired “X-O” diagram.
The selection tables of the following
page show all the “X-O” combinations.
For the purpose of this example, the
applicable portion of those tables is
shown in Table 47-386.
For more information visit: www.eaton.com
Incoming
Pushbuttons & Indicating Lights
30.5 mm Class I Division 2 Hazardous Locations
10250T/E34 Series, Selector Switch Selection
Line
HAND OFF AUTO
HAND OFF AUTO
X O O
O O X
X O O
O O X
HAND
OFF
AUTO
Outgoing
Outgoing
Circuit
Circuit
Table 47-386. Example Selection Table
Now to make the cam selection, make
a simple worksheet such as below.
(1) or (2) = mounting location from chart
above:
It becomes obvious that cam 3 is the
better choice because the series con-
nection can be avoided, making it
simpler to wire.
Step 4: Contact Block Selection.
Having selected the cam, contact block
selection is simply a matter of deter-
mining if you require one NO-NC contact
block (Cat. No 10250T1H) or two. Given
the limitations of the factory sealed
contact block and the desired “X-O”
application, you may have circuits that
will not be needed — as seen here
with the two additional NC circuits.
(1) or (2) = mounting location from chart
above.
Step 5: Selector Switch Operator.
Lastly, you have to choose from the
many types of operators — knob and
lever in various colors or keyed. Also
what combinations of maintained and
spring return functions are required.
Selection of these operators can be
found on Page 47-235. For the above
example you may want a 3-position
maintained black knob, cam 3 —
Catalog Number 10250T1323 (or
34VHBK1).
The Complete Switch: 10250T1323 (or
34VHBK1) with two 10250T1H or for
one composite catalog number —
10250T726BK (or E34EX726BK) found
on Page 47-231.
No. Desired
1
4
Wired in series.
Qty
X O O
O O X
2
Circuit &
Operator
Position
X O O
O O X
Catalog No.
10250TIH
(1)NO – (2)NC
Cam Code #2
Contact
Blocks &
Mounting
Location
1
NO
Cam 2
(2)NC
NC
2
NO
(1)NO
(1)NC
Cam Code #3
Contact
Blocks &
Mounting
Location
1
NO
(1)NO
Cam 3
Cam 3
(2)NC
(2)NO
2
NO
(2)NO
47-233
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