NEWSHEET 21

Product Selection

A simple guide to a comparison between Proline "DIGITAL" and competitor "ANALOGUE" operating concepts

9 point summary of the limitations of an analogue Linear Heat Detection system are:

1. Analogue is NOT (in an actual installation situation) the 100% recoverable cable claimed - the system works on a resistance/length/temperature relationship. The longer the sensor cable length exposed, the lower the alarm temperature. As ALL overheat and incipient fire conditions are localised events the shorter the length of sensor cable you heat the higher the temperature necessary to generate the required alarm resistance change. Temperatures being above cable destruct levels. With Proline digital, the alarm temperature - say 68C - is fixed regardless of 1% or 100% exposure. I cannot understand the importance some place on a recoverable cable - if there were to be a fire, would it not be that much more than just a linear heat sensing cable system needed replacement?  With Proline only the short fire damaged section requires replacement not the total zone length.
2. Design lengths are restricted by ambient tempertures. The higher the ambient, the shorter the zone length possible therefore the more interface units you require and the higher the system price.Even at low ambients 1000m is the maximum zone length specified by one manufacturer. With Proline, you can use 2kms or longer sensor cable lengths per Proline interface unit - regardless of ambient temperature.
3. You cannot quote an accurate alarm temperature to your customer unless you know before hand the EXACT length of sensor cable that will be exposed in an overheat or fire condition. With Proline you can specify 68C, 88C or 105C ( the 3 alarm temperature options available) because it is not length dependant.
4. Analogue Sensor cable can require "heat shrink" joints and end terminations. Apply too much heat to the joint/termination and you damage the sensor cable. Apply too little heat and moisture can get into the cable causing false alarms and/or faults with what is a resistance averaging device. With Proline, standard junction boxes, crimps or even terminal blocks with insulation tape around (only if acceptable to your customer) are required for joints/terminations.
5. Analogue sensor cables are  FM approved only. Proline is FM approved AND UL listed
6. FM Approval maximum recommended spacing (30 ft /9.0m) between ceiling /roof runs is less than Proline sensor cable (35ft/10.6m) - meaning more Analogue sensor cable is required and a higher system price.
7. The narrower spacing means Analogue is less responsive than Proline. Proven by UL, FM and independantly by Apollo fire detector oven test.
8. Analogue interface units have fire and fault output contact signalling. Proline ZI-01 has colour coded LCD which indicates ALARM POINT LOCATION in feet or metres, volt free fire and fault output contacts and RS232 serial link option (to repeat the LCD alarm location display on a central panel or PC).
9. EMI or RFI could cause a problem to analogue systems. Proline is immune to both EMI and RFI