Apollo 55000-640APO XP95 I.S. Optical Smoke Detector

Name: Apollo 55000-640APO XP95 I.S. Optical Smoke Detector – Datasheet
Brand: Apollo
SKU: 55000-640APO

An intrinsically safe optical smoke detector on the XP95 protocol

The Apollo 55000-640APO is the XP95 Intrinsically Safe (I.S.) optical smoke detector. It works on the light-scatter principle and is described by Apollo as ideal where slow-burning or smouldering fires are likely, and well suited to escape routes. It is unaffected by wind or atmospheric pressure.

The detector connects to a two-wire loop that carries both data and a 14 V to 22 V dc supply. It uses the XP95 native protocol and is Discovery compatible. The unit is calibrated to read 25 plus or minus 7 counts in clean air, and a count of 55 corresponds to the EN 54 alarm sensitivity level.

Technical specifications

Parameter	Specification
Part number	55000-640APO
Detection principle	Photo-electric detection of light scattered forward by smoke particles
Supply voltage / modulation	14-22 V; modulation voltage 5-6 V
Quiescent current	160 microamps; power-up surge 1 mA
Sensitivity	0.15 dB/m (3.395 %/m)
Alarm / remote LED current	700 microamps / 500 microamps (internally limited)
Ex classification	Ex ia IIC T4 GA (up to +60 C); Ex ia IIC T5 GA (see temperature note)
Certificates	BASEEFA BAS02ATEX1289X; IECEx BAS 12.0091X
Operating temperature	-20 to +60 C (T4); -20 to +60 C listed for T5 in the data table
Storage temperature	-30 to +80 C
Humidity	0-95 % RH, no condensation or icing
IP rating	IP 44
Dimensions / weight	100 mm diameter x 42 mm height; 105 g
Materials	White flame-retardant polycarbonate housing; nickel-plated stainless steel terminals
Standards / directives	EN 54-7 vibration, impact and shock; EMC 2014/30/EU; CPR 305/2011; Marine Equipment 2014/90/EU; ATEX 2014/34/EU

How it behaves on an intrinsically safe loop

A safety barrier is a mandatory part of an I.S. system, and its high series impedance limits how many I.S. detectors can be fitted on a circuit. Apollo states that a typical I.S. circuit has a maximum load of 20 detectors, restricted to 12 optical detectors in an IIC environment, depending on the barrier type, the devices fitted and how many detector LEDs the control panel lets illuminate at once.

A drive point is provided for a remote LED indicator. Unlike the standard XP95 range, the remote LED cannot be controlled independently of the integral LED because it is connected in series with it, so lighting it does not increase loop current. The Apollo MiniDisc Remote Indicator, part number 53832-070, is suitable using terminals B and C. System certification requires the LED and its terminations to be protected to at least IP20 and segregated per BS EN 60079-14.

Ordering and what to confirm before ordering

The 55000-640APO is a detector head; it needs a compatible XP95 mounting base and a barrier and control panel suited to I.S. circuits. Confirm base part number, barrier type and loop loading with the panel manufacturer. Hazardous-area approvals apply only to the whole system as certified, so check the zone, gas group and temperature class for your installation. A SIL 2 variant (55000-640SIL) exists on the manufacturer site, so quote the exact suffix. For standard areas see the Apollo 55000-600 XP95 optical smoke detector.

Apollo’s datasheet notes that conformity with the EMC Directive does not confer compliance on connected apparatus.

Documents and quotation

The manufacturer document for the 55000-640APO is listed under Documents on this page: Apollo PP5114 XP95 I.S. Optical Smoke Detector specification (Issue 3, 2026). Browse related items in Fire & Gas Detectors. For price, availability and lead time, send an RFQ with the exact part number, quantity and project details; Seven Star LLC is an independent supplier based in Muscat and confirms stock and delivery on quotation.

Apollo XP95 loop devices

XP95 is the Apollo range of analogue addressable detectors and interfaces. Besides detectors, it includes modules that link the loop to other equipment. The Sounder Control Unit on our site is one of these: it lets the control panel switch and supervise a circuit of conventional sounders fed from an external power supply.

Ordering Apollo devices: what we need

Apollo identifies each device by a part number in the form 55000-000, for example 55000-182 for a DIN-rail sounder control unit. Send that number, the range name printed on the device, the quantity, and the make and model of your control panel. For detectors, state whether mounting bases are needed and which type.