Littelfuse M1500 User Manual

• 6 inputs for PT100 resistors

• 6 current outputs 4-20mA according to DIN

EN 60751 & IEC 751

• Can be used together with the SELCO

M3000 Analog Alarm Annunciator

• Cost effective and highly reliable compact

design

• 50 hours burn-in before final test

• Operating temperature range:

-20°C to +70°C

• Flame retardant enclosure

• DIN rail and screw mounting

The M1500 provides a cost effective solution

and includes 6 current transmitters in one box

to be connected to temperature resistors. The

unit can be used in connection with the

SELCO M3000 Analog Alarm Annunciator.

The PT100 resistors are connected at the

inputs illustrated in fig. 1. The resistance of

PT100 resistors depends on the temperature.

The reason for the middle terminals (e.g.

terminal 2) is to compensate for resistance

in the cable.

The outputs are 4-20mA current out-puts, also

illustrated in fig. 1.

The output current is 4-20mA for

temperatures 0-160°C, 0-300°C or 0-600°C

according to DIN EN 60751 & IEC 751.

The temperature range is selected for each

input on the front panel.

The ratio between current and temperature is
linear, meaning that for 0-160°C PT100
resistors, 0°C corresponds to 4mA, 80°C
correspond to 12mA and 160°C correspond to
20mA.

Fig. 2 illustrates the connections to one input
group of the M3000 Analog Alarm
Annunciator. The reference resistor R should
be used with M3000-20 Analog Alarm Annunciator,
but not with the newer version instrument M3000-30.

The resistor should be 261 ¼W with a tolerance of 0.1%.

The M1500 has been designed and tested for use in harsh environments. The unit is based on standard components, -

providing long term durability.

The M1500 carries the CE label and has been approved by the Russian Maritime Register of Shipping.