This document provides information about EMEX central power supply systems for emergency lighting. It discusses why EMEX power is a good choice due to its high performance, precision engineering, and easy maintenance. It also outlines key benefits like extended system life, long battery life, flexibility, modular construction, and enhanced testing capabilities. The document provides guidance on properly specifying an EMEX system, including defining luminaire details, power consumption, and power factor considerations. Tables list available EMEX central power unit options for 1 hour, 3 hour, and 3 hour three phase systems.

1. Engineer’s Companion
EMEX Central Power Supply Systems

2. Why choose EMEX Power?
Effective emergency power from Emergi-Lite
Why choose EMEX Power?
With exceptional performance, precision
engineering and easy maintenance, it’s
simple to see why EMEX Power is the assured
choice for engineers and consultants
preparing centrally powered emergency
lighting schemes.
EMEX Power is manufactured at our ISO 9001
approved facility in the UK and has been specifically
designed to power emergency lighting in a mains
fail or evacuation situation. Therefore the system
carries the capacity to start the full luminaire load
without mains supply present, offers excellent
overload and recharge capabilities, and includes
enhanced protection with MCB’s throughout.
Furthermore, as a power supply system to
emergency lighting, EMEX Power meets all the
requirements of ICEL 1009 and BS EN 50171
product standards.
In effect, EMEX Power has been designed to
meet the most stringent demands of emergency
lighting scheme designers, engineers, building
owners/occupiers and the requirements of local
fire authorities.
Key benefits of EMEX Power:
Extended system life: EMEX Power system design life
in excess of 20 years, providing excellent ROI
Long life batteries: Battery life up to twice that of a
self-contained system
System flexibility: Flexible design enables the
EMEX system to manage any load power factor, from
zero to unity, at any output power up to the
maximum rated KVA
Modular construction: Five key components for
minimal stock holding of parts, easy maintenance
and reduced system downtime/cost of repair
Enhanced testing facility: Fully compatible with
EMEX Test automated testing solution (available
as either integral touch-screen – EMEX TS – or
remote PC)
With all its benefits, deciding in favour of EMEX
Power is simple, yet choosing the correct size of
system requires in-depth assessment. This
companion booklet has been prepared to help
engineers/designers specify their exact
requirements and to provide clear guidance on the
range of EMEX Power products available.
Turn over for full details on how to specify an EMEX Central Power Supply System

3. Specifying EMEX Power
Specifying EMEX Central Power
Supply (CPS) Systems
Emergency lighting schemes are designed to
protect life. In the event of a fire, or mains
supply failure, escape route lighting and exit
signs must illuminate and maintain power for
a sufficient period of time to allow occupants
to safely evacuate the building.
Therefore, for an engineer working on a centrally
powered emergency lighting scheme, the key
requirement is to ensure that the central power
supply unit specified is capable of meeting the
power consumption demands of all the emergency
luminaires planned in the system, for the duration
of time needed for safe evacuation.
Furthermore, in these energy conscious times,
engineers and scheme designers need to balance
the power requirements of the system with the
needs of the building user for ongoing energy
efficiency. Too little power designed into the system
risks failure to start the emergency luminaires on
demand. However, overspecifying requirements
simply leads to ongoing energy wastage and
increased costs for the building owner/occupier.
Proper assessment of the power consumption needs
and wattage of the luminaires in the scheme can
overcome these concerns.
Key specification criteria
To accurately determine the size of CPS system
required for an emergency lighting scheme,
consider and define the following:
Luminaire type and manufacturer (including
luminaire part numbers if available)
Quantity of luminaires in the scheme (per type)
Actual wattage for each luminaire type
Required VA for each luminaire type
Both the VA requirement and the actual wattage
(the luminaire circuit wattage) requirement of the
load should be specified, since they each affect the
sizing of a different system component. Essentially,
wattage establishes the battery size, VA confirms
the size of inverter. Establishing both ensures the
best match between the requirements of inverter
to load.
The ratio between VA and wattage is termed the
Power Factor (PF) of the luminaire, and is highly
important to CPS specification and sizing.
Essentially the Power Factor determines the
efficiency of the luminaire. Power figures for lamp
types can vary significantly between manufacturers.
Obtaining manufacturer’s data for each luminaire is
therefore the best accurate method for calculating
total power consumption.
Occasionally, only limited information on luminaire
wattage and VA is available. In these instances,
where the required VA of the equipment is known,
assume a load power factor of Unity PF to calculate
the wattage requirement of the load and the
inverter size required. Where the wattage of the
luminaires is provided, and is less than 20w,
assuming 0.85 PF would be the best practice.
Emergi-Lite offers CPS systems to suit both 0.85 and
Unity Power Factor.
Best Practice – Quantified Luminaire Schedules
Providing key information to the CPS system supplier ensures specification of the most appropriate system
for the emergency lighting scheme, and the most accurate quotation!
Consider putting together a quantified luminaire schedule (hardcopy or electronic format) along the
following lines to assist with system specification:
Luminaire Type Luminaire Name Part Number Manufacturer Power Consumption Wattage Quantity in Scheme
8w Linear T5 Day-Lite XW13111HF Emergi-Lite 10.70 9.00 100
28w2D Camarque CLQ28PHF Emergi-Lite 34.00 32.60 20
For further advice assistance, please contact Emergi-Lite Central Power Supply Technical Support.
UK Sales Technical Support:
Tel: +44 (0)113 281 0600, Fax: +44 (0)113 281 0601, email: emergi-lite.sales@tnb.com

4. Power Factor (PF) considerations
EMEX AC/AC Central Power Supply (Static Inverter)
systems distribute power at mains voltage that can
utilise all the lamps within a luminaire at full ballast
lumen factor (BLF) for the luminaire.
In order to get the full light output from the tube
it is necessary to put more than the actual rated
lamp wattage into the luminaire, since, in addition
to energy that is given out as light, some is also
lost in the form of heat. This energy affects the
battery size.
Additionally, some ballasts (in particular switch start
magnetic types), operate at a higher current than
the rated power, i.e. less than Unity Power Factor.
This means that there is a part of the power input
that does not consume energy, but circulates from
source to luminaire. This “wattless” component has
to be supplied from the CPS, and causes its VA
rating to be increased. This does not affect the
battery size.
This variance between required load VA and rated
lamp wattage must be considered. The ratio of
actual watts / VA is known as the Power Factor.
Power factors of some ballasts can be as low as
0.33. If all luminaires in the system have this Power
Factor, then the CPS would have to be three times
larger than for a Unity PF load! Figures for lamp
types can vary significantly between manufacturers.
Therefore, the total actual power consumption in
watts and VA must be assessed.
A key contributor to Power Factor is the type of
control equipment used by the luminaire. Two
types of control equipment are readily available for
emergency luminaires – Electronic High Frequency,
or Switch Start. High Frequency is much more
efficient than cheaper Switch Start luminaires, with
much lower power losses, but sizes below 20w can
have a low PF.
The chart below shows clearly the proportion of
losses to output wattage to be expected for a
58 watt tube using a Switch Start versus HF ballast.
80
Total Watts / VA Requirement
Switch Start
HF
60
50
40
30
20
10
0
Total VA Circuit Watts Rated Lamp Watts 58w
70
60
50
40
30
20
10
0
Thus a 58w HF luminaire is almost 20% more
efficient than the Switch Start variant, requiring
considerably less energy to achieve rated
output wattage.
Middle East Sales Technical Support:
Tel: +971 (0)4 609 1635, Fax: +971 (0)4 609 1636, email: emergi-lite-salesme@tnb.com

5. System Selection
Central power unit selection
Emergi-Lite EMEX Central Power Supply Systems
are dual rated to allow selection of an appropriate
system to either commercial or ICEL ratings.
ICEL rating is derived by de-rating by 20% the
commercial system. In effect, these systems include
20% spare capacity to provide the scheme designer
opportunity for future revision, or expansion, of
the scheme.
The tables right identify the most popular CPS
systems available from Emergi-Lite. Below are
example calculations based on the differing
requirements of High Frequency and Switch Start
control gear to provide guidance for your
own calculations.
Design examples
These examples show how the same load using
different control equipment can conclude in very
different CPS systems. The examples are based on a
3 hour Single Phase system.
High Frequency control equipment load calculation Switch Start control equipment load calculation
Emergi-Lite emergency luminaires
Emergi-Lite offers a full range of luminaires and
exit signs for use with Central Power Supply
systems. All luminaires include High Frequency
control gear for maximum efficiency and can be
addressed for use with the EMEX Test automatic
testing solution for CPS systems.
Please contact you regional Emergi-Lite sales
manager for more information about our range
of slave 230V luminaires.
Far East Sales Technical Support:
Tel: +65 6720 8828, Fax: +65 6720 8780, email: asia.inquiry@tnb.com
Luminaire
Type
Power
Consumption
Wattage Quantity
8w Linear T5 11.00 9.00 28
58w Linear 56.10 55.00 119
Total Power Consumption: Total Wattage:
(28 x 11.00) + (119 x 56.10)
= 6983.90
(28 x 9.00) + (119 x 55.00)
= 6797.00
+ 20% Additional Capacity (to comply with BS EN 50171):
= 8380.68 = 8156.40
Luminaire
Type
Power
Consumption
Wattage Quantity
8w Linear T5 13.80 12.00 28
58w Linear 79.30 69.00 119
Total Power Consumption: Total Wattage:
(28 x 13.80) + (119 x 79.30)
= 9823.10
(28 x 12.00) + (119 x 69.00)
= 8547.00
+ 20% Additional Capacity (to comply with BS EN 50171):
= 11787.72 = 10256.40
The difference between power consumption and wattage for the High
Frequency luminaires is less than 3%, indicating that a Unity Power
Factor system would best manage the emergency lighting scheme.
Having added 20% to comply with BS EN requirements, the commercial
rating values for CPS systems are considered.
Following review of the tables right, CPS unit ELD8310.090 proves the
logical choice, as it provides up to 9000 VA / watts of power.
By comparison, if a 0.85 PF system was specified, the smallest system
available would be ELD9000.019, a 10,500 VA system, to ensure
sufficient wattage is provided (up to 8,925 watts.)
The difference between power consumption and wattage for the Switch
Start luminaires is greater than 14%.
Having added 20% to comply with BS EN requirements, the commercial
rating values for CPS systems are considered.
Following review of the tables right, either the 0.85 PF CPS unit
ELD9000.021 (15,000 VA / 12,750 watts) or Unity PF system
ELD8310.120 (12,000 VA / 12,000 watts), is possible.
N.B.: When selecting luminaires, Switch Start luminaires are not
compatible with LTC addressable interfaces.

6. Unity PF range Switch Start/0.85 PF range
1 Hour Single Phase 220 – 240V 50Hz (adjustable)
Commercial rating
VA / watts
ICEL rating
VA / watts
Cabinet
Qty.
Part
No.
1,500 1,250 1 ELD8110.015
3,000 2,500 1 ELD8110.030
4,500 3,750 1 ELD8110.045
6,000 5,000 1 ELD8110.060
7,500 6,250 2 ELD8110.075
9,000 7,500 2 ELD8110.090
10,500 8,750 2 ELD8110.105
12,000 10,000 2 ELD8110.120
15,000 12,500 2 ELD8110.150
18,000 15,000 3 ELD8110.180
21,000 17,500 3 ELD8110.210
24,000 20,000 3 ELD8110.240
3 Hour Single Phase 220 – 240V 50Hz (adjustable)
Commercial rating
VA / watts
ICEL rating
VA / watts
Cabinet
Qty.
Part
No.
1,500 1,250 1 ELD8310.015
3,000 2,500 1 ELD8310.030
4,500 3,750 2 ELD8310.045
6,000 5,000 2 ELD8310.060
7,500 6,250 2 ELD8310.075
9,000 7,500 3 ELD8310.090
10,500 8,750 3 ELD8310.105
12,000 10,000 3 ELD8310.120
13,500 11,250 3 ELD8310.135
15,000 12,500 4 ELD8310.150
16,500 13,750 4 ELD8310.165
18,000 15,000 4 ELD8310.180
19,500 16,250 4 ELD8310.195
21,000 17,500 5 ELD8310.210
22,500 18,750 5 ELD8310.225
24,000 20,000 5 ELD8310.240
3 Hour Three Phase 220 – 240V/380 – 415V 50Hz
(adjustable)
Commercial rating
VA / watts
ICEL rating
VA / watts
Cabinet
Qty.
Part
No.
4,500 3,750 2 ELD8330.045
9,000 7,500 3 ELD8330.090
13,500 11,250 3 ELD8330.135
18,000 15,000 4 ELD8330.180
22,500 18,750 5 ELD8330.225
27,000 22,500 6 ELD8330.270
31,500 26,250 7 ELD8330.315
36,000 30,000 7 ELD8330.360
40,500 33,750 8 ELD8330.405
45,000 37,500 9 ELD8330.450
49,500 41,250 10 ELD8330.495
54,000 45,000 11 ELD8330.540
58,500 48,750 12 ELD8330.585
63,000 52,500 14 ELD8330.630
1 hour Single Phase 220 – 240V 50Hz (adjustable)
Commercial rating
VA / watts
ICEL rating
VA / watts
Cabinet
Qty.
Part
No.
1,500 / 1,275 1,250 / 1,060 1 ELD9000.001
3,000 / 2,550 2,500 / 2,125 1 ELD9000.002
4,500 / 3,825 3,750 / 3,188 1 ELD9000.003
6,000 / 5,100 5,000 / 4,250 1 ELD9000.004
7,500 / 6,375 6,250 / 5,310 1 ELD9000.005
9,000 / 7,650 7,500 / 6,375 1 ELD9000.006
10,500 / 8,925 8,750 / 7,430 2 ELD9000.007
12,000 / 10,200 10,000 / 8,500 2 ELD9000.008
15,000 / 12,750 12,500 / 10,625 2 ELD9000.009
18,000 / 15,300 15,000 / 12,750 2 ELD9000.010
21,000 / 17,850 17,500 / 14,875 3 ELD9000.011
24,000 / 20,400 20,000 / 17,000 3 ELD9000.012
3 hour Single Phase 220 – 240V 50Hz (adjustable)
Commercial rating
VA / watts
ICEL rating
VA / watts
Cabinet
Qty.
Part
No.
1,500 / 1,275 1,250 / 1,060 1 ELD9000.013
3,000 / 2,550 2,500 / 2,125 1 ELD9000.014
4,500 / 3,825 3,750 / 3,188 2 ELD9000.015
6,000 / 5,100 5,000 / 4,250 2 ELD9000.016
7,500 / 6,375 6,250 / 5,310 2 ELD9000.017
9,000 / 7,650 7,500 / 6,375 2 ELD9000.018
10,500 / 8,925 8,750 / 7,430 3 ELD9000.019
12,000 / 10,200 10,000 / 8,500 3 ELD9000.020
15,000 / 12,750 12,500 / 10,625 3 ELD9000.021
18,000 / 15,300 15,000 / 12,750 4 ELD9000.022
21,000 / 17,850 17,500 / 14,875 4 ELD9000.023
24,000 / 20,400 20,000 / 17,000 5 ELD9000.024
3 hour Three Phase 220 – 240V/380 – 415V 50Hz
(adjustable)
Commercial rating
VA / watts
ICEL rating
VA / watts
Cabinet
Qty.
Part
No.
27,000 / 22,950 22,900 / 19,500 6 ELD9000.090
36,000 / 30,600 30,600 / 26,000 7 ELD9000.091
45,000 / 38,250 38,200 / 32,400 8 ELD9000.092
54,000 / 45,900 45,900 / 39,000 10 ELD9000.093
63,000 / 53,550 53,500 / 45,400 10 ELD9000.094
These tables provide information on Emergi-Lite’s
most popular AC/AC Central Power Supply systems.
All systems are available with integral touch-screen
for EMEX Test automated testing software. For this
option, simply add suffix /TS to the Part Number
(i.e. ELD8310.030/TS.)
Larger systems, 2 hour duration systems, and 110V,
50V 24V CPS systems are available. If the required
system size or duration is not shown here, please
contact Emergi-Lite to discuss your requirements.
UK Sales: Middle East Sales: Far East Sales:
+44 (0)113 281 0600 +971 (0)4 609 1635 +65 6720 8828

7. The complete emergency lighting
central system testing solution
EMEX Test is a highly flexible emergency
lighting automated testing solution. With the
ability to support virtually any type of slave
230V luminaire, including LED, EMEX Test
affords freedom of choice for engineers,
consultants and end-users alike.
Emergency lighting regulations stipulate periodic
testing of emergency lighting systems to ensure
correct operation in the event of a mains failure,
with records needing to be kept for all tests
conducted. This task is now the responsibility of
the building owner/occupier. Emergency lighting
testing can be a highly disruptive exercise, with
manual record keeping a laborious task. EMEX Test
has been designed to provide the ideal solution for
luminaire testing.
EMEX Test delivers highly effective testing of
emergency lighting lamps, control gear and central
power supply all at the touch of a button. Periodic
luminaire tests can be scheduled at times of
minimum disruption, with test reports generated
and stored automatically. Moreover, periodic
testing can be configured to comply with the
relevant BS EN and NFPA standards.
Multiple static inverter systems can be networked
to a single control PC. Building management system
communication, including BACNET and LONWORKS
formats, can be linked to the system. Network
nodes enable engineers to access test reports and
system controls using a laptop PC from any point on
the data cable.
Comprehensive, flexible, effective – EMEX Test is
the automated testing solution for CPS systems.
To discover more about the benefits of specifying
EMEX Test, please contact your regional
Emergi-Lite sales manager.
EMEX Test components
MXC substation MXT data repeater MXD4 substation
LTC addressable interface
Part No. Description
ELD9500.912 EMEX Test software package
ELD9500.030 MXC substation
ELD9500.016 MXD4 4-way addressable substation
ELD9500.120 MXT100 data repeater
ELD9500.121 MXT200 data repeater
ELD9500.036 LTC addressable interface
ELD9500.039 EMEX Test input node
ELD9500.038 EMEX Test remote test input package
ELD9500.910 MXKP station adapter kit
For full product details please refer to our EMEX Central Power Supply Catalogue.

8. UK OFFICE
Thomas Betts Limited
Emergi-Lite Safety Systems
Bruntcliffe Lane
Leeds
West Yorkshire
LS27 9LL
United Kingdom
Tel +44 (0)113 281 0600
Fax +44 (0)113 281 0601
emergi-lite.sales@tnb.com
www.emergi-lite.co.uk
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Belgium
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EMEX8PP1-0409
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LIGHTING AND FIRE DETECTION
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