LPS 1236 Issue 1.1 Requirements for control panels for diesel engine driven pumps used in automatic sprinkler installations
Environmental protection
The control panel housing shall be in non-flammable material and provide a degree of protection at least equal to IP 54 (BS EN 60529:1992 – Specification for degrees of protection provided by enclosures (IP code)), or be suited to its environment where the conditions are more demanding.
Access to control panel
The enclosure door shall be fitted with a suitable locking device, requiring the use of a key or special tool, in order to restrict access to authorised personnel only. It shall not be possible to open the panel door without having first isolated the AC main supply.
Controllers shall be located as close as practicable to the pump sets they control, and shall be within sight of the pump set. The controller must not be mounted directly on the pump set and must not be exposed to any undue sources of vibration.
Power supply
Mains feed
The main AC supply switch operating handle shall be outside the housing of the equipment, and interlocked with the enclosure door. If mains power supply is turned off, the panel shall continue to run powered by its batteries. A switch accessible from inside the panel enclosure shall be provided to isolate the battery power when required for maintenance.
The fuse or circuit breaker ratings shall be clearly shown at a point near the devices.
The metal earth for the housing shall be connected directly to a terminal which provides for connection to an earthing point. This terminal shall be labelled.
Batteries
As per LPS 1240 (pump sets), two separate 12 or 24V DC battery power supplies shall be provided for engine starting and control panel backup. They shall be used for no other purpose. They shall be maintained on charge by two chargers connected to the mains.
Batteries shall be either:
Open nickel – cadmium prismatic rechargeable cells complying with BS EN 60623 (Secondary cells and batteries containing alkaline or other non-acid electrolytes. Vented nickel-cadmium prismatic rechargeable single cells) (or BS 6260 (Specification for open nickel-cadmium prismatic rechargeable single cells – withdrawn), or:
Lead-acid Plante positive batteries complying with BS EN 60896 part 1 Stationary lead-acid batteries. General requirements and methods of test. Vented types (or BS 6290 part 1 – Lead-acid stationary cells and batteries. Specification for general requirements (withdrawn) and BS 6290 Part 2 – Lead-acid stationary cells and batteries. Specification for the high-performance Plante positive type).
Each battery shall have the design capacity to rotate the engine at 0 °C and 760 mm mercury atmospheric pressure for not less than 10 cycles each of not less than 15 s cranking and not more than 10 s rest. At the end of the energized part of each cycle the engine cranking speed shall be not less than 120 r/min whilst power is applied.
Chargers
Two totally independent, constant, potential/current limited battery chargers are to be provided.
The battery chargers shall be independently powered from the controller single phase A.C. supply via surge limiting fuses or circuit breakers. It shall be possible to remove either charger whilst leaving the other operational.
During standby conditions each battery charger must be continuously energised and permanently connected to its respective battery set. The charger outputs for normal float conditions should be set in accordance with the battery manufacturer’s recommendations to allow the optimum trickle current to flow through the batteries, ensuring that they are maintained in a fully charged condition with minimum water loss. The controller circuits’ and ECM standing load on the batteries should be automatically compensated for (ECMs included for future use). Chargers shall be rated to ensure batteries are restored to 90% of the batteries ampere hour rating within 24 hours.
During battery cranking the controller circuits shall automatically turn off both battery chargers. 3
Boost charge
A boost charge facility shall be provided for charging to a higher voltage again in accordance with battery manufacturers recommendations. The boost control (if the panel design requires one) should be accessible only from within the panel housing.
Operation of the chargers is to be monitored, and in the event that either charger output fails, or if either battery set becomes faulty or disconnected, then the ‘charger fault’ alarm should operate. Charger alarms are to be inhibited while the chargers are turned off during cranking.
Operational parameters
The control panel shall ensure the automatic and manual operation, control and monitoring of:-
When powered up, normal operation must be ensured at temperatures between 0°C and 50°C or over a wider temperature range if specifically requested by the designer.
In addition, the panel shall be equipped with devices which will permit the transfer of information and data, as detailed in section 3.5.
Automatic starting system
Automatic start-up shall be by means of a contact which opens to initiate a start. This shall be triggered by a de-energised pressure switch signal.
This sequence shall be initiated automatically on receipt of a signal indicating pressure drop in the fire protection system. The automatic start facility shall remain functional at all times, with only the following exceptions:
switch at the control panel, protected from unauthorised use by a key- locked device)
The automatic starting sequence shall make six attempts to start the engine. The system shall switch over automatically to the other battery after each cranking attempt. Each attempt shall be of a minimum of 15 seconds duration. There shall be a maximum pause of 10 seconds between each attempt.
If either battery has insufficient power (determined by monitoring the rotation speed during cranking) to crank the engine during any stage of the cranking cycle, further cranks must automatically be made drawing power from the other battery to complete the six attempt sequence.
The control voltage shall be drawn from both batteries simultaneously. Once started the pump set must continue to run until shut down manually, by means of a shutdown push button located on the enclosure door and connected to the stop control.
After the fire pump has started an engine driven frequency generator, common magnetic pickup or ECM shall provide a signal to the electronic speed sensor in the controller to cancel further cranking and automatically re-set the controller for future operation.
Pressure switches, for example on the engine lubricating system or pump discharge, shall not be used as a means of de-energising the starter motor.
The controller shall also provide an output signal to drive the engine mounted tachometer, the nature of the signal being determined by the type of instrument fitted.
Emergency manual starting system.
An over-ride emergency manual start facility shall be provided, protected by means of a frangible cover, or quick access front, and shall be operative at all times even with the automatic start switch in the OFF position. Starting shall be provided by both sets of batteries in parallel. There shall be no delay in operation of the emergency manual start facility.
Test facility for manual starting.
A manual start test button and indicating lamp shall be provided to permit periodic testing of the manual electric start system without breaking the frangible cover over the emergency start button.
The indicating lamp shall be marked “Operate manual start test button if lit “.
The pushbutton and indicating lamp may be a combined device. The manual start test push button shall only be brought on line after an automatic engine start followed by a shut down or after six repeated unsuccessful attempts to start automatically. Either of the two conditions shall cause the indicator lamp to light and bring the manual start test button on line.
The power shall only be drawn from the battery which did not provide power for the last cranking attempt.
When a test manual start has been carried out, the circuit used for this purpose shall automatically become inoperable and the indicator lamp shall be extinguished. The automatic start facility shall be available, even when the manual start test button circuit is activated.
Note:- During test, after the engine is stopped there shall be a maximum period of 10 seconds before a start sequence can be initiated by the controller (either by a pressure drop or an emergency manual start).
Outputs
Indicators
Visual indication is to be provided by solid state indicators having clearly viable labels with relevant data as shown in table 1.
A common lamp test pushbutton shall be provided.
The principle of visual indication used for safety equipment is to be as follows:-
defective and is not able to operate normally. Action required.
- ‘AUTOMATIC START UNAVAILABLE’ output signal signifying:-
Any switch or protective device which prevents the pump starting automatically is in “off” or “tripped” condition.
- ‘ENGINE RUNNING’ output signal signifying the pump is operating
Meters – measurement indication
The following parameters must be measured independently to an accuracy of ±5% with the actual measurements being displayed:-
- The charging level of the chargers, by means of ammeters (one per charger) permitting readings with maximum increment scale of 0.5A.
- For all the measuring equipment, the normal functional ranges and units must be stated, preferably by direct display on the dial.
Terminal numbering
In order to maintain compatibility between engine sets and controllers supplied by different manufacturers, a numbering system has been introduced which shall be adhered to. See table 24
Numbering for fans, louvers and alarm contacts as per individual manufacturer’s standard.
Auxiliary and Supplementary Functions
Any device or function of a supplementary nature provided in the equipment and not covered by this present specification shall not interfere with the functional requirements set out by the specification and referenced documents; they shall further comply with the data relating to them.
Electrical and key component schematics.
Manufacturers recommended functional test procedures (routine).
Manufacturing drawings.
Drawings showing views of the panel from the front, from above and from the side, showing the indicator lamps, pushbuttons and inscriptions (a photograph shall also be provided of the front face).
Sectionalised drawing of the panel, showing the positions of the various items and devices (these shall be labelled).
Drawing showing the positions of the terminal blocks and cabling, labelled with cross- reference to the schematics.
Each drawing shall have the dimensions marked on and be accompanied by a listing of all the items making up the equipment and protection, where this is appropriate (paint, varnish, etc.).
Means to safely disable engine for service and maintenance activities.
Test certificates, where applicable, showing compliance with Directives listed on page three.
TYPE TESTING
The manufacturer shall submit a complete panel to the LPCB, including:- Connecting cabling between the panel and the batteries;
- Two batteries of the same voltage as those used in the installation but of a lower capacity, so as to ensure merely the operation of the devices included within the panel.
- The device which will indicate the start-up or failure to start of the motor. The input and output characteristics of this device must be specified in the technical data sheets.
The designer shall also provide a technical dossier, covering the items listed in Appendix 3.
Function tests
Verification tests shall be carried out to confirm that all the functionality required by this standard and referenced documents is provided by the controller.
Battery chargers
The batter charges shall be checked for correct operation at 85% and then 110% of nominal AC line voltage.
A functional test is to be carried out at 85% of nominal battery voltage.
Vibration testing
The purpose of this test is to evaluate the ability of the components of a controller to withstand mechanically and to function formally when they are subjected to vibrations, which may occur under normal operating conditions in the installation, or during transportation.
APPARATUS AND METHOD OF OPERATION
This test is carried out with a vibrating device, used at a frequency of 20 Hz with a peak-to- peak amplitude of 0.8mm – that is, an acceleration equivalent to 0.64g.
The equipment, positioned in its normal operating plane, is subjected to vibrations for a period of 30 minutes, perpendicular to its plane of attachment and then for thirty minutes in two orthogonal directions parallel to this plane.
Electrical safety checks (AC Circuits)
In addition to statutory electrical safety design and test requirements applicable to the region of use: