Boiler house

Remote Alarm and Shutdown Panels

for Boilers

The requirements of PM5

Level controls

Local regulations may restrict the use of this product to below the conditions quoted.

In the interests of development and improvement of the product, we reserve the right to change the specification without notice.

© Copyright 2014

The Health and Safety Executive Guidance Note PM5 'Automatically controlled steam and hot water boilers' specifies some requirements

for remote alarms and the remote shutdown of boilers.

Some of the relevant sections are:

Paragraph 50 ......... when a boiler is not continually supervised it is not enough to have an alarm on the boiler. Alarms should be provided

at points where they can be heard by persons who are competent to take appropriate action

Paragraph 51 ........ When a boiler is subject to partial supervision it is recommended that an emergency device which will shut off the

burners should be located remote from the boiler house and should be clearly marked. (See paragraph 13).

Paragraph 13 ......... there should always be someone available on site who is competent to respond to alarms, and to take appropriate

action which at a minimum, may be to shut the boiler down safely before calling for the assistance of a trained boiler attendant.

Remote alarm panel

These requirements can be met by the installation of a 'hard wired' remote alarm panel installed at a continuously manned location such

as a telephone exchange or security point. Suitable procedures should then be established and training given on the action to take in the

case of an alarm. A typical installation is shown below.

2.3.40

Equipment required

1. To be fitted in each boiler panel:

Boiler house

1 off

1 off

3 off

1 off

Transformer 240 V (or 110 V) to 48 V. Provides low

voltage power supply to panel.

Boiler shutdown relay 48 V coil. Shuts down burner

when de-energised.

Boiler alarm relays 240 V (or 110 V) coils. For

signalling 1st low, 2nd low and high level alarms.

Any number of additional alarms may easily be

signalled.

Key operated local/remote switch. Can be used to

prevent remote alarms during manual tests and

maintenance of the boiler.

Multi-core cable, 4 cores per boiler

Typically 1000 m long using standard cable

Alarm and shutdown panel in remote location

2. To be fitted at the remote location:

1 off Alarm and shutdown panel for one or more boilers. Incorporates for each boiler an alarm lamp, alarm buzzer, mute button with

relay and a mushroom headed stop button which latches in the stop position and can only be reset by a key. 4 terminals per boiler.

Three boiler alarm and shutdown panel shown.

Panel dimensions:

For 1 or 2 boilers

300 x 300 x 140 mm deep

For 3 or 4 boilers

500 x 400 x 140 mm deep

3. Cable

4 cores per boiler. PVC insulated, PVC sheathed, unscreened multi-core cable can be used. Cable lengths up to 1000 m are possible

using cable size 0.5 mm2 per core. Longer lengths would require large cable. A suitable cable can be obtained from ESD Electronic

Services of Harlow in lengths up to 500 m, their type numbers are:

4 core 16-2-4 A

8 core 18-2-8 A

12 core 16-2-12 A

18 core 16-2-18 A

System operation

During normal operation the local / remote switches must be in 'remote'. The boiler alarm relays in each boiler panel are normally energised

which in turn keep the alarm relays in the remote panel energised and no lights show. In the case of a boiler alarm, the relays are

de-energised, the boiler alarm lamp in the remote panel lights and the buzzer sounds. The operator should then press the stop button

and may mute the buzzer. The alarm lamp continues to show whilst there is an alarm.

When the boiler attendant goes to the boiler house he should switch to 'local', rectify any faults on the boiler and set it running. The remote

stop button must then be reset with a key, and the switch in the boiler house returned to 'remote'.

If a boiler panel is switched off all power is removed from that section of the remote alarm panel so no boiler alarm is signalled. Similarly

when a boiler is switched to 'local' the alarm lamp and buzzer in the remote panel will not operate. In the case of a break in the cable the

boilers will be shut down immediately but could be restarted by switching to 'local' in the boiler house.

Testing

Any alarm system should be tested regularly. In the case of high integrity self-monitoring low level alarms, the remote panel can be tested

during the regular weekly test of the low level alarms.

TI-S75-06

AB Issue 3