Where:
• t
amb
= Measured (or set) ambient temperature (can be set in
̊
C or in
̊
F)
• t
max
= Maximum temperature (can be set in
̊
C or in
̊
F) for the protected object
• k
max
= Ambient temperature correction factor for the maximum temperature
• t
min
= Minimum temperature (can be set in
̊
C or in
̊
F) for the protected object
• k
min
= Ambient temperature correction factor for the minimum temperature
• t
ref
= Ambient temperature reference (can be set in
̊
C or in
̊
F, the temperature in which the
manufacturer's temperature presumptions apply, the temperature correction factor is 1.0)
Figure. 5.4.12 - 119. Ambient temperature coefficient calculation (a three-point linear approximation and a settable correction
curve).
As can be seen in the diagram above, the ambient temperature coefficient is relative to the nominal
temperature reference. By default the temperature reference is +15 °C (underground cables) which
gives the correction factor value of 1.00 for the thermal replica.
A settable thermal capacity curve uses the linear interpolation for ambient temperature correction with
a maximum of ten (10) pairs of temperature–correction factor pairs.
A
AQ
Q-C215
-C215
Instruction manual
Version: 2.07
168
© Arcteq Relays Ltd
IM00040