Eaton MTL 9491-PS User manual

MTL 9491-PS
Intrinsically safe power supply
October 2016
INM MTL 9491-PS Rev 3
Instruction manual
MTL intrinsic safety solutions

ii INM9491 Rev 3
DECLARATION OF CONFORMITY
A printed version of the Declaration of Conformity has been provided separately within the
original shipment of goods. However, you can find a copy of the latest version at
http://www.mtl-inst.com/certificates

iii
INM9491 Rev 3
CONTENTS
DECLARATION OF CONFORMITY .......................................II
1 FEATURES...........................................................1
2 DESCRIPTION ........................................................1
3 DIN-RAIL INSTALLATION METHOD.........................................3
3.1 Protection of equipment ....................................................3
3.2 DIN rail mounting ........................................................3
3.3 Power bus - Installation and use .............................................5
3.4 Earth rail and tagging accessories ............................................6
3.5 Assembly ...............................................................8
4 BACKPLANE MOUNTING METHOD .......................................10
4.1 Accessories.............................................................10
4.2 Protection of equipment ...................................................10
4.3 Backplane mounting .....................................................10
4.4 Backplanes – identification and tagging ......................................12
4.5 Backplanes - earth rails ...................................................14
4.6 Backplanes – power supply connections.......................................14
4.7 Fitting 9491-PS modules to backplane ........................................14
5 ENVIRONMENTAL....................................................16
6 WASTE REMOVAL INFORMATION ........................................16
7 APPROVALS .......................................................16
8 FM CERTIFICATION INFORMATION .......................................16
9 ATEX & IECExCERTIFICATION INFORMATION ...............................17

iv INM9491 Rev 3
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1
INM9491 Rev 3
1 FEATURES
♦Isolated power supply
♦Zone 2 and Division 2 mountable
♦DIN-rail or backplane mounting
♦ATEX / IECEx approvals
♦FM (USA & Canada) approved
♦200mA @10.9V DC - Ex ia IIB Groups C, D output
♦400mA @11.8V DC - Ex ib IIB output
♦Power over Ethernet option (PoEx)*
♦Multiple outputs achieved by ganging 9491 modules using 24V DC power distribution
backplane
*Note – PoEx is a simple adaptation of the IEEE 802.3af Power over Ethernet (PoE) standard to
bring the benefits to the 9400 Range of Hazardous Area devices. This allows two spare pairs in the
existing Cat5e cable to distribute the power supplied to a 9466 Ethernet Switch (Power Sourcing
Equipment – PSE) to each of the devices connected to its five ports (PD – Powered Device). This
adaptation is necessary due to restrictions for Hazardous Area use. It is not implied that the device
conforms to the 802.3af (PoE) standard.
2 DESCRIPTION
The 9491-PS Power Supply is the recommended 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 any one of the 94xx Series 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.
The output can be from either the Ex ia IIB Groups C, D or Ex ib IIB output connectors depending
upon application. The ‘ib’ IIB output providing a higher useable output power where the Gas Group
and Zone allows. See Figures 2.1 and 2.2 for connection details.
INM9491 Rev 3
9491-PS IS Power Supply

2INM9491 Rev 3
Each 9491-PS can power a single 946x-ET Ethernet module.
It is not permitted to connect to both ia and ib outputs on the same 9491-PS module.
If multiple outputs are required for several Ethernet modules, there is a power distribution backplane
available to simplify the 24VDC input connection to the modules, or alternatively a number of them
can be DIN-rail mounted with a convenient “Powerbus” input.
The 9491-PS module has LED power indication for both input and output (see Figure 2.3) 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.
Hazardous area Safe are a
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Figure 2.1
Zone 0
Ex ia IIB
application
Hazardous area Safe are a
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Figure 2.2
Zone 1
Ex ib IIB
application
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Figure 2.3
9491-PS
top label and
LED indicators
Terminal Function
1 Ex ia IIB Groups C,D output +ve
2 n.c.
3 Ex ia IIB Groups C,D output –ve
4 n.c.
5 Ex ib IIB Output +ve
6 Ex ib IIB Output –ve
13 Supply –ve (Vs–)
14 Supply +ve (Vs+)
Zone 0
Zone 1
Terminal Function
1 Ex ia IIB Groups C,D output +ve
2 n.c.
3 Ex ia IIB Groups C,D output –ve
4 n.c.
5 Ex ib IIB Output +ve
6 Ex ib IIB Output –ve
7, 8 & 9 Supply –ve (Vs–)
10, 11 & 12 Supply +ve (Vs+)
Table 2.1
DIN-rail
mounting
connections
Table 2.2
Backplane
mounting
connnections

3
INM9491 Rev 3
3 DIN-RAIL INSTALLATION METHOD
This section deals with mounting the individual 9491-PS power supplies on DIN rail, for backplane
mounting see Section 4.
WARNING: If this module is to be connected to intrinsically safe apparatus, it must be installed,
operated and maintained only be trained competent personnel and in accordance with all
appropriate international, national and local standard codes of practice and site regulation and in
accordance with the instructions contained here. See also Sections 7, 8 and 9 for approvals and
important conditions of safe use.
3.1 Protection of equipment
When the power supply is mounted in a safe area ensure that the local environment is clean and
free of dirt and dust and note the ambient temperature considerations given in Section 5.
WARNING: When mounted in a Zone 2 hazardous area the module must be protected by a
suitably certified enclosure.
3.2 DIN rail mounting
Mount the 9491-PS power supplies on low-profile (7mm) or high-profile (15mm) type T35 (top-hat) DIN-
rail to EN50022, BS5584, DIN46277; this is available from Eaton, in 1 metre lengths (THR2 DIN rail).
It is recommended that, in normal practice, the DIN rail is earthed to ensure personnel safety in the event
of mains being put accidentally on the rail.
See Figure 3.1 for power supply dimensions.
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Figure 3.1
9491-PS package
dimensions
& connections

4INM9491 Rev 3
3.2.1 Mounting power supplies on DIN rail
Clip power supplies onto type T35 DIN rail as shown in Figure 3.2, with the blue signal plugs facing
towards the hazardous-area wiring. To remove an power supply from the rail, insert a screwdriver blade
into the clip as shown and lever the clip gently outwards; pivot the power suppy off the rail. Allow a
maximum mounting pitch of 16.2mm for each unit.
3.2.2 Wiring up power supplies
Depending on the installation, it may be easier to wire up power supplies with power plugs either in
place or removed. Either way, allow sufficient free cable to permit plugs to be removed easily for future
maintenance and/or replacement purposes.
Power conductors
The removable power plugs are fitted with screw clamp terminals. Note that the conductors should be
between 14 and 24 AWG (1.6 and 0.5mm dia) in size. Plugs, located on top of the modules, are
mechanically keyed to fit in only one position. The input power plug slots into the socket at terminals 13
and 14 on the safe-area side of each module.
Making connections
a) Trim back the insulation of conductors by 12mm.
b) Check the terminal assignments shown in section 6 or on the side label of the unit.
c) Insert conductors according to the terminal assignments and tighten screws.
If the wires are to be fitted with crimp ferrules, 10–12mm is the recommended length of the metal tube.
If longer ones are used, they must be trimmed to 12mm before fitting.
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 
Figure 3.2
DIN rail mounting
and removal
of module
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Figure 3.2
Removable
power plugs

5
INM9491 Rev 3
Finishing
Wire up individual power supplies in accordance with wiring schedules. Daisy-chain power supply
connections between individual power plugs or use the power bus (see section 4.1).
Segregate hazardous- and safe-area wiring into separate trunking or looms wherever possible to avoid
errors and maintain a tidy installation.
3.2.3 Ambient temperature considerations
Ambient temperature limits for unenclosed power supplies are from 0°C to +70°C with units close-
packed.
3.3 Power bus - Installation and use
A PB-8T power bus kit enables power supply terminals (13 and 14) of up to 8 installed 9491-PS power
supplies to be linked to a standard 24V power supply. The bus consists of a chain of power plugs and
different lengths are available to suit various numbers of modules as follows.
3.3.1 Check to make sure the bus length is correct for the number of modules involved.
3.3.2 If the number of modules is less than the maximum number the chain will support, cut off
the surplus power plugs at the tail end of the chain - leaving sufficient cable to attach
further power plugs if it becomes necessary later.
3.3.3 Insert power plugs into the power terminals on the safe- area side of each module in
sequence.
3.3.4 Connect the power supply source to the tail end of the chain (using the insulation
displacement connectors [Scotchloks] provided if required).
Notes:
1. To avoid excessive voltage drop or over-current, DO NOT connect power buses in series.
2. Surplus sections can be used (and, if required) connected together provided the cut ends are safely
terminated and/or connected together. Use single ferrules with a crimp tool or insulation displacement
connectors (Scotchloks). Suitable ferrules and connectors are provided with the kits.
– +
Optional insulation
displacement
connectors
x2
Figure 3.3
Power bus
wiring, joining
and terminating

6INM9491 Rev 3
3.4 Earth rail and tagging accessories
This section explains how to specify and assemble earth rail and tagging strip accessories for the
9491-PS power supplies. The accessories consist of mounting brackets, earth rails, tagging strips and
associated parts. They provide facilities for earthing, terminating cable screens and tagging (identifying)
the positions of individual units.
3.4.1 Parts list
IMB57 Insulating mounting block (Figures 3.4, 3.5 & 3.6)
One required at each end of a tagging strip/earth rail. Suitable for low-profile (7.5mm) and high-
profile (15mm) symmetrical DIN rail.
ERB57S Earth-rail bracket, straight (figure 3.10)
Nickel-plated bus bar; supplied with two push fasteners, one earth-rail clamp (14mm, 35mm
2
) and one
earth cable clamp (10mm, 16mm
2
).
Note: ERB57S is the preferred choice of earth-rail bracket. It is usually fitted in the upper slot on insulating
mounting block IMB57.
Where the earth rail is required to be positioned at a lower height and to allow access to the IMB57
mounting screws, the straight earth-rail bracket ERB57S can be inserted in the lower slot, but only after
insulating mounting blocks IMB57 are clamped to the DIN rail. This may not be possible if, for example,
trunking is fitted. In this case, fit offset earth-rail bracket ERB570 (see figure 3.4 & 3.10) in the upper slot:
the mounting blocks can then be fitted in a restricted space with this bracket already fitted.
ERB570 Earth-rail bracket, offset (figure 3.10)
Nickel-plated bus bar ; supplied with two push fasteners, one earth-rail clamp (14mm, 35mm2) and
one earth cable clamp (10mm, 16mm2).
ERL7 Earth rail, 1m length (figure 3.10)
Nickel-plated bus bar; may be cut to length.
TAG57 Tagging strip, 1m length (figure 3.10)
Cut to size. Supplied with tagging strip label.
TGL57 Tagging strip labels, set of 10 x 0.5m
Spares replacement, for use with TAG57 tagging strip.
MS010 DIN rail module spacer, 10mm, pack of 5 (figure 3.8)
Grey spacer; one required between each 9491-PS and any adjacent module on a DIN rail, to provide
10mm air-circulation space between modules.
ETM7 Earth terminal, bag of 50 (figure 3.9)
For terminating cable screens and 0V returns on the ERL7 earth rail. For cables ≤4mm2.
TH5000 Tag holder
Spares replacement.
Connectors
Spares replacement: HAZ1-3, HAZ4-6, HAZ-CJC, PWR5000, SAF7-9, SAF10-12 (SAF1-3 and SAF4-6
grey connectors, also available for use in safe-area applications).