MTL Instruments 9491-PS Data sheet

• Isolated power supply

• Zone 2 & Division 2 mountable

• DIN-rail or backplane mounting

• ATEX / IECEx certified

• FM / FMC approved

• 200mA @ 10.9V DC - Ex ia IIB

Groups C, D output

• 400mA @ 11.8V DC - Ex ib IIB output

• Power over Ethernet option

• Multiple outputs achieved by ganging

9491-PS modules using 24V DC power
distribution backplane

technical datasheet

technical datasheet

9491-PS

12V DC Intrinsically Safe Power Supply

The 9491-PS Power Supply is the preferred
method for supplying the 9460-ET series of
intrinsically safe Ethernet modules and is
based on an isolating power supply. It takes
a 24V DC safe area / Zone 2 / Division 2
supply and produces an intrinsically safe,
12V DC nominal output capable of powering
the Ethernet modules mounted in a Zone 1/
Division 1 hazardous area. The 9491-PS may
be mounted in a safe area, Zone 2 or Division
2 hazardous area.

Each 9491-PS can power a single Ethernet
module. In order to provide multiple outputs
required for several Ethernet modules, the
9491-PS power supply module is ganged up
to the required number of ways, either DIN­rail mounted or using the power distribution
backplane to simplify the 24VDC input
connection to the modules.

The 9491-PS module has LED power
indication for both input and output along
with internal current limiting and electronic

auto-reset circuit breaker action to protect the
module in the event of its output being short
circuited or overloaded. This also minimises
the power dissipation during the fault to a
negligible level, thus improving reliability.

The output can be from either the Ex ia IIB
Group C, D or Ex ib IIB output connectors
depending upon application. The ‘ib’ IIB
output provides a higher useable output
power where the Gas Group and Zone allows.

EPS9491 Rev5 030510

[e-mail]

SPECIFICATION

See also System Specification

POWER INPUT

Separately powered
Input voltage

24V DC (20–30V)

Input current

350mA

Input protection

Fuse + supply reversal diode

Connectors (see dimension drawing)

DIN rail mounting: screw terminals – capacity 2.5mm2

Backplane mounting: multipin connector

POWER OUTPUT

[Ex ia] output (pins 1 & 3)

Graph shows normal working range & total available range

Minimum output voltage Equivalent circuit

12.1

9.7

Output
voltage
(V)

stranded or single core

maximum

6W

12.1V minimum

DIMENSIONS (mm)

Intrinsically safe (IS)
output connectors

118.8

(Height from top of DIN rail)

+

+

13 56





O/P

104.8

Optional TH5000 tag holder for individual
module identification.
Accepts tag label 25 x 12.5 ±0.5mm, 0.2mm thick

SUPPLY

109.8

PWR

9491-PS 12VDC POWER

13


+

14

15.8

121.8

(Height from circuit board)

Output current (mA)

400

[Ex ib] output (pins 5 & 6)

Minimum output voltage Equivalent circuit

12.1

Output
voltage
(V)

11.6

Output current (mA)

400

maximum

1.3W

12.1V minimum

Connectors

9491-PS is supplied with two IS output connectors.
Capacity 2.5mm2 stranded or single core
(When using crimp ferrules for the IS connectors the metal tube
length should be 12mm and the wire trim length 14mm.)

ISOLATION

Isolation - input to output

Um = 253V rms

SAFETY

Location of module

Safe area, Zone 2, Division 2

Location of field wiring

[Ex ia] output

Zone 0, IIB hazardous area
or Class 1, Div 1, Groups C, D hazardous location

[Ex ib] output

Zone 1, IIB hazardous area

Certification Code

See approvals

Safety description

See certificate

Power input for
backplane mounting

7



14

+

Power input for
DIN-rail mounting

MECHANICAL

Mounting

DIN rail or power distribution backplane

Dimensions

See diagram

Weight

130 g

ENVIRONMENTAL

Ambient temp

Operating 0°C to +70°C
Storage −20°C to +70°C

Relative Humidity

5 to 95% RH (non-condensing)

Ingress Protection

Select enclosure to suit application, see certificate for information

LED INDICATORS

OFF Flash ON

Pwr (green) 24V power fail N/A 24V power OK

IS (green) IS power fail output overload

or short circuit
present

IS power OK

The given d ata is only int ended as a pro duct desc ription an d should not be r egarded a s a legal war ranty of pro per­ties or gu arantee. In t he interest o f furthe r technica l developments, we re serve the right to ma ke design change s.

EUROPE (EM EA): [phone] THE AMERICAS: [phone] ASIA-PACIFIC: [phone]

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EPS9491 Rev5 030510