Bosch Appliances 3.5 manual 8.4Fan control, PRS-1P500, PRS-2P250and PRS-4P125

Models: 3.5

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8.4Fan control

Praesideo 3.5 Installation and User Instructions 4 Amplifiers

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8.4Fan control

The PRS-1P500, PRS-2P250 and PRS-4P125 amplifiers, from HW version 06/00 onwards, have a fan monitoring circuit that detects the actual fan rotation. This detection is needed for compliancy to the standards UL864 and UL1711, for use in the USA. Additionally the internal fans need to run at full speed for compliancy to these standards. A jumper on the main PCB selects between two positions:

Normal (factory default) - The fans are temperature controlled, normally running at low speed and switching to high speed in case the temperature exceeds a certain level. Fan monitoring is not activated.

Full speed - The fans run at full speed continuously. Fan monitoring is activated. Do not enable Switch amplifiers to standby (see section 44.4) for this selection, because in standby the fans are stopped and a fault would be generated.

The jumper is indicated on the PCB as X18; connection 1-2 selects Normal, connection 2-3 selects Full speed. See figure 8.15.

PRS-1P500, PRS-2P250 and PRS-4P125

X18

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2

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figure 8.15: Jumper X18 provides fan control for PRS-1P500, PRS-2P250 and PRS-4P125

Bosch Security Systems 2011-02

Page 144
Image 144
Bosch Appliances 3.5 manual 8.4Fan control, PRS-1P500, PRS-2P250and PRS-4P125