Meilhaus Electronic ME-630 Series, Manual

Page: 15 / 35

3.3 Relays
The real current carrying rating of the ME-630 depends on several
conditions, which are described in the following.
Important Notes:
Choose sufficient wire gauges for your external wiring (e.g.
0.5 mm
2 at 2 A). Note the resulting power dissipation and provide
a sufficient ventilation of the housing. We strongly advise you to
stick to the following maximum values for the carrying rating of the
ME-630:
 When using the connector cable ME-AK-D78(/1): max. 0.5 A
per relay
 When using an external wiring with sufficient dimensioning:
- Permanent load at 25 °C environmental temperature: max.
2°A per relay
- Short-term load: max. 3.5 A of single relays
The total power dissipation P
G
of all relay channels of the board
must not exceed 12.8 W!
The resistance R
n
of the board per channel (connector, track, relay
contact) is typ. 200 m
Ω
(max. 250 m
Ω
). Use the following formula
for the power dissipation per channel P
n
at I
n
= 2 A (with n =
1…16):
P
n
= I
n
2 · R
n
= 22 A · 0.2
Ω
= 0.8 W
i.e. the total power dissipation is:
P
G
= P
n=1
+ … + P
n=16
≤ 12.8 W