The Westminster Series 60 Intrinsically Safe range of smoke and heat detectors are intrinsically safe devices specifically developed for use in hazardous areas.
Versions
An ionisation smoke detector, integrating ionisation smoke detector and five grades of heat detector are available.
Function
The Series 60 I.S. detectors are functionally equivalent to their standard Series 60 counterparts.
They differ in design only in that their circuits and construction have been modified to conform to the requirements of EN 50014:1977 and EN 50020:1977 (which are identical to BS5501: Part 1 and BS5501: Part 7 respectively).
All types are certified EEx ia IIC T5 at ambient temperatures up to 40°C or T4 at ambient temperatures up to 60°C.
The BASEEFA certificate number, applicable to all types, is Ex96D2439.
Mechanical Construction
Series 60 I.S. detectors use the same outer casings as the standard Series 60 detectors, and therefore share the same dimensions.
The detectors are identified as intrinsically safe by a printed legend around the lid (see photo above).
The detectors must be used with the certified Series 60 I.S. base which is considered for certification purposes to be part of the detector.
The base is marked with the legend 'PART OF BASEEFA CERTIFIED DETECTOR'. Use of any other base will invalidate the approval.
System Requirements
The detectors must be used in a system which includes suitable safety barriers and which is certified by BASEEFA or other competent body.
Westminster Fire Detectors have obtained system certification for a system incorporating any of the following safety barriers:
- Any certified 28V/300. Shunt safety barrier;
- MTL3043 or MTL4061;
- Pepperl + Fuchs KHD0-ICS-Ex151 or Ex251;
- Pepperl + Fuchs KHD0-CS-Ex1.54 or Ex2.54;
- Pepperl + Fuchs KFD0-ICS-Ex151 or Ex251;
- Pepperl + Fuchs KFD0-CS-Ex1.54 or Ex2.54;
- The BASEEFA system certificate number is Ex97D2054.
The system certification allows up to 20 Series 60 I.S. detectors to be connected to a single barrier circuit with an end-of-line resistor of not less than 1.8k. However, it must be ensured that the voltage available at each detector is above the minimum specified in the quiescent condition.
It is also important to ensure that the alarm load is suitable for the control and indicating equipment.
The system certification also allows the use of remote LED indicators. These may be connected to individual detectors or may use a connection common to two or more detectors as shown below:
Electrical Characteristics
The following characteristics apply at 24 V DC and 25°C unless otherwise stated:
- Supply voltage 14 to 28V DC (polarised);
- Quiescent current Ionisation detectors 45μA Heat detectors 50μA;
- Alarm load 310 (typical) in series with 2 volt drop;
- Alarm current (minimum) 10mA (maximum) 60mA;
- Alarm voltage 5V minimum (at least 10V for good LED illumination).
Installation Guidelines
The detectors must be installed in accordance with the appropriate local code of practice e.g. BS5435 in the UK. The following points should be noted in addition:
- It is important that detectors are installed in such a way that all terminals and connections are protected to at least IP20 when the detector is in the base;
- If the base is mounted on a conduit box with a diameter of less than 85mm then the base should be fitted with the Series 60/XP95 Back plate, part number 45681-233;
- The base contains an earth terminal which is provided simply as a convenient termination point for cable screens. It is not essential for the correct operation of the detector and is not intended to be used for a safety (I.S.) earth.
Approvals
Series 60 I.S detectors have been approved by LPCB to EN54. They have also been approved for marine use by the following bodies:
- American Bureau of Shipping;
- Bureau Veritas;
- Det Norske Veritas;
- Germanischer Lloyd;
- Lloyds Register of Shipping;
- Maritime and Coastguard Agency.