48
Version 17
Safe-E-
Stop™
User Guide
8.8.4 MSD Connections
Before installing the MSD, prepare an electrical wiring diagram that defines all electrical interface connections
between the system and the equipment being controlled.
Cattron also advises you to first read the following topics of discussion and to locate and refer to the example
mainline drawing provided.
Do not exceed the relay rating (see Appendix V). When connected to contactors, protect these relay contacts
with suitably-rated transient suppression devices to maximize contact life expectancy and prevent whiskering.
Overload protection <=8A for the relays and 1A for the power supply. Means to isolate the MSD from power when
required should be in place. The supply voltage is 24Vdc nominal (9-36Vdc), maximum current is 1A, nominal
current at 24V is 250mA. The MSD is fitted with a protective fuse next to the DC input terminal (Cattron part
number PRT-0001852) rated at
1A. An optional wide range (85-264VAC 47-63Hz 1A) power supply is available
from Cattron.
Care should also be taken to provide suitably-rated overload protection and isolation device. When using an
external power supply, this should also have a 1A overload protective device.
The safety inputs are rated at 24Vdc +- 4Vdc, omni-directional (non-polarized).
8.8.5 MSD Terminals
The MSD is fitted with spring clamp terminals to ensure reliable connections are continuously maintained.
These terminals require the use of a size 3 screwdriver to open the clamp for release (CAUTION, do not press the
release clamp too hard or it may damage the terminal). The ferrules are simply pushed in for insertion.
The use of ferrules is required to eliminate any possibility of wire strands shorting to adjacent terminals and to aid
insertion into the spring clamps.
8.8.5.1 Terminal and Wire Specifications
Wire sizes smaller than 0.459 mm
2
, 24AWG and a temperature rating of lower than 80° Celsius are unallowed, for
electrical safety certification compliance.
*For voltages greater than 24Vdc wire sizes of 18AWG (0.82mm
2
) minimum are recommended, but in all cases
the wiring must be correctly rated for its intended service,
Wire gauge: https://en.wikipedia.org/wiki/American_wire_gauge
Insulation:
http://iq.ul.com/awm/stylepage.aspx?style=1015
Table 13: Terminals Maximum Wire Capacity
I
NPUTS AND
O
UTPUTS
P
OWER
I
N
T
EMPERATURE RATING
U
SE OF
F
ERRULES
Size mm
2
0.459* to 1.5
0.459* to 2.5
>80°C (176F)
Required
Size AWG
24* to 16
24* to 12
>80°C (176F)
Required
