EN 12845 Fire Service and Monitoring Centre Alarm Connection

Type A and Type B signals, the alarm receiving centre model, PSTN, GSM and IP transmission paths, and the real errors we meet on site.

A logistics warehouse had an OH3 sprinkler installation. At the annual test the flow switch operated and the control panel lit red — but nothing left the building. The operator said "we had a GSM dialler fitted". Stripping the module revealed that the SIM had been restricted by the network three months earlier, blocking outbound SMS only. The panel showed "transmitted"; in reality nobody was being told. That is exactly what the alarm transmission annex exists to prevent: it requires the alarm signal to reach a defined, continuously attended point without interruption.

Where it sits in the standard

The normative alarm transmission annex covers two things:

• Functions to be monitored: a table listing which alarm is transmitted at which type.
• Alarm levels: dividing signals into fire (Type A) and technical fault (Type B).

Its opening paragraph states that alarms are connected to a panel in the sprinkler control room or pump room and transmitted onward "according to their importance", to a continuously attended point inside or outside the facility. Where there is a direct connection to the fire service, the test procedure is agreed with the authority.

Type A and Type B alarms

There is no numbered "Level 1-2-3-4" scheme in the annex; that is a confusion with the EN 50136 transmission classes. The EN 12845 scheme has two types:

Signal	Type
Water flow alarm (flow switch)	A
Low town main pressure	B
Pump room flow detector	A
Priming tank low level	B
Electric pump: running	A
Electric pump: demand / failure to start / no power	B
Diesel pump: running	A
Diesel pump: auto mode off / failure to start / controller fault	B
Trace heating circuit fault	B
Pre-action type A low pressure	B
Dry pipe or pre-action low air pressure	B
Zoned system: valve partly closed, low main pressure	B
Zoned system: zone flow or installation flow	A
Supervised stop valve partly closed, liquid level, power failure, low room temperature	B

The logic is simple: Type A means "there may be a fire now, respond"; Type B means "if a fire starts, the system may not work properly — come and check". The annex allows "pump running" to be treated as Type B depending on local conditions, a deliberate flexibility to reduce false calls.

Transmission paths

EN 12845 does not list which transmission medium to use; it requires transmission to be reliable and the line to be testable. The media used in European practice:

• PSTN copper: the classical dialler. If the line is physically cut, the panel raises a line fault. Disappearing rapidly as operators withdraw copper.
• GSM dialler (2G/4G): one SIM, one operator, one path. Acceptable for low risk, inadequate where the insurer requires more. Exposed to SIM expiry, coverage and jamming.
• IP (Ethernet or fibre): supervised by continuous polling every 90–180 s. The backbone of modern monitoring connections.
• Redundant (dual path): IP plus GSM, with EN 50136-1 class SP4/SP5 or DP3/DP4 systems detecting a line fault within minutes.

Taking the "continuously attended point" requirement seriously means supervising the line too. A GSM dialler that stops sending at month end does not, in fact, satisfy the annex.

The alarm receiving centre

The European model has three layers:

1. EN 12845: which signals, at which type, on the sprinkler side.
2. EN 50136-1: classification of the transmission system carrying the signal — transmission time, notification time, redundancy.
3. EN 50518: the alarm receiving centre itself — physical security, 24/7 staffing, standby power, failover to a second centre.

When signing a monitoring contract, name all three: "EN 12845 signal table, EN 50136-1 SP4 transmission, EN 50518 certified centre". Otherwise an insurance dispute turns into an argument about transmission that existed but was never supervised.

Additional insurer requirements

EN 12845 is the minimum. Insurer frameworks generally add:

• Two independent transmission paths, on different networks.
• Type A signals passed to the fire service within 90 seconds without verification — flow straight to emergency dispatch.
• Type B signals reported in writing to the operator within four hours.
• Annual test records archived by the monitoring centre.
• The monitoring contract attached to the insurance policy.

Turkish practice

Direct automatic connection to the fire service is not common infrastructure in Turkey; municipal fire control rooms work by telephone. In practice:

• The flow alarm from the sprinkler panel goes either to a 24/7 site security room or to a private monitoring centre.
• The centre receives the signal, verifies it by telephone ("fire or test?"), and calls the emergency number if verification is negative or there is no answer.
• That chain satisfies the annex — but if verification takes more than 60 to 120 seconds, it may not satisfy the insurer's condition.

BYKHY requires the sprinkler alarm signal to be connected to the fire detection and warning system, leaving onward notification to the operator. So BYKHY says "have a panel, make a noise, keep records"; the "continuously monitored" condition comes from the monitoring contract. On projects taking EN 12845 as a contract condition, the annex fills that gap.

A field error: an expired GSM SIM

The opening example is very common. The typical root causes:

• The SIM is on a consumer tariff requiring use every six months, rather than a machine-to-machine tariff.
• The dialler's poll interval is 24 hours, so a line cut a week earlier is only noticed a day later.
• The centre does not process the "no signal" alarm with a timestamp, so it goes unnoticed until the moment of panic.

The fix: an M2M SIM, IP polling at no more than 180 seconds, and a contract clause requiring the centre to telephone the site within 30 minutes of signal loss. At the annual test, deliberately cut the GSM or IP path as well as tripping the flow switch, and expect a call back.

Comparison with NFPA 72

NFPA 72 defines three categories of supervising station alarm system: central station service (an independent, certified centre), remote supervising station (a public authority or other monitoring point), and proprietary supervising station (the facility's own control room). EN 12845 makes no such distinction, saying only "permanently attended location". NFPA gives certification and response time metrics (90 s to the receiver, a further 90 s onward); EN 12845 gives no response time metric, and that gap is filled by EN 50136 and the insurer.

Common errors

• The flow switch drives only a local siren and nothing is transmitted — Type A missing.
• The pump "no power" signal appears on the panel but does not leave the building — a critical Type B omission.
• A GSM dialler with no line supervision.
• The monitoring contract has expired and nobody renewed it.
• Pre-action or dry pipe low air pressure not connected to the panel.
• Trace heating fault not monitored — on a dry system the first freeze is how you find out.
• The "partly closed" signal on zone valves shown on the panel mimic but not transmitted.

Design decision list

1. Put the signal table into the mechanical specification verbatim — which signal is Type A and which Type B, in writing.
2. Choose the transmission medium by risk class: a single path is acceptable for light hazard, dual paths recommended for OH3 and above.
3. Write the monitoring contract with EN 50136 and EN 50518 references.
4. Add a line-cut test to the annual test procedure.
5. Where the insurer sets additional conditions, write the response time into the contract.
6. For BYKHY, also connect the common alarm signal to the fire detection panel so the two systems see each other.

Summary

The annex comes down to two sentences: transmit the fire signal, and every fault that could disable the system, without interruption to a continuously attended point. The Type A/B split sets the signal's priority, EN 50136 the reliability of transmission, and EN 50518 the standard of the receiving centre. Because there is no direct fire service connection infrastructure in Turkey, the monitoring centre model is effectively the only option, and keeping the contract and the line alive is the operator's responsibility. A green light on the panel does not prove the signal left the building — without testing, line supervision and a call-back discipline, the annex is not satisfied.

Frequently asked questions

Does EN 12845 require a direct fire service connection?

No. The annex requires a "continuously attended location", which may be an on-site watch, a monitoring centre or the fire service. Where a direct connection exists, the test procedure is agreed with the authority.

What is the difference between Type A and Type B?

Type A is a fire alarm — flow, alarm valve, pump running. Type B is a technical fault — no power, diesel out of auto, low pressure. Both go to the attended location, but with different priority.

Is GSM alone sufficient?

Acceptable for light hazard risk; for ordinary hazard and above, or where the insurer requires it, a second independent path is recommended. Line supervision is essential either way.

Is there automatic fire service connection in Turkey?

There is no standard infrastructure. Monitoring companies receive the signal, verify it and call the emergency number. Verification time must stay within the threshold the insurer accepts.

Is an NFPA 72 supervising station the same as an EN 12845 monitoring centre?

Conceptually similar but with a different requirement set. NFPA 72 defines three categories with UL 827 certification; EN 12845 says only "permanently attended location", with the detail filled in by EN 50136 and EN 50518.

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