Danfoss VLT HVAC Drive FC 102, Operating Instructions Manual

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1.8 Symbols, Abbreviations, and
Conventions
Abbreviation Description
ETR Electronic thermal relay.
LCP Local control panel.
NC Not connected.
PNP Positive negative positive (transistor).
TNF Nominal response temperature.
Table 1.2 Abbreviations
Abbreviati
on Reference Description
ATEX ATEX Directive
94/9/EC ATmosphere EXplosibles
HFT EN IEC 61508 Hardware fault tolerance: HFT=n
means that n+1 faults could cause a
loss of the safety function.
PDS/SR EN IEC
61800-5-2 Power drive system (safety-related).
PFD EN IEC 61508 Average probability of failure on
demand, value used for low-
demand operation.
SFF EN IEC 61508 Safe failure fraction [%]; percentage
of safe failures and dangerous
detected failures of a safety function
or a subsystem related to all failures.
SIL EN IEC 61508
EN IEC 62061 Safety integrity level.
STO EN IEC
61800-5-2 Safe Torque Off.
SRECS EN IEC 62061 Safety-related electrical control
system.
Table 1.3 Abbreviations Related to Functional Safety
Conventions
Numbered lists indicate procedures.
Bullet lists indicate other information and description of
illustrations.
Italicised text indicates:
•
Cross-reference.
•
Link.
•
Parameter name.
Introduction
VLT
®
PTC Thermistor Card MCB 112
6 Danfoss A/S © 01/2015 All rights reserved. MG33V302
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