©
National Instruments Corp.
13
cFP-RLY-425
Calculate the maximum current as
Example 1. If eight channels carry 5 A each, the total current is
8(5 A)
2
=
200 A
2
. As shown in Figure 11, the module can output
this total current with an ambient temperature up to 60 °C.
Example 2. If two channels carry 5 A each and six channels carry
2 A each, the total current is 2(5 A)
2
+
6(2 A)
2
=
74 A
2
. The module
can output this total current with an ambient temperature up to
70 °C.
Initial path resistance ........................ <50 m
Ω
Note
DC path resistance typically remains low for
the life of the relay. At the end of relay life, the path
resistance rises rapidly above 1
Ω
. Load ratings apply
to relays used within the specification before the end of
relay life.
Off-state leakage current
At 125 VDC ............................... 0.03
µ
A
At 250 VAC ................................ 2
µ
A
Expected relay life
Mechanical ................................. 2
×
10
7
operations
Electrical
At 5 A, 30 VDC ................... 1.5
×
10
5
operations
At 3 A, 120 VAC.................. 1.5
×
10
5
operations
At 5 A, 250 VAC.................. 3
×
10
4
operations
Recommended cycle rate
With up to 3 A load .................... 1 s ON, 1 s OFF
With 3 A or greater load............. 3 s ON, 3 s OFF
Relay operate time ............................ <10 ms
Relay release time............................. <7 ms
Contact bounce time ......................... <1 ms
Contact material................................ Gold-plated silver alloy
I
n
( )
2
n
0
=
7
∑
