BA 3527161/02 EN
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6.2 Adjustment via built-in Matching Resistance
MRB110-1 or MRB110-2
A) Determine the required gradient in °C (or K) (from
the heat-run tests).
B) Check the current (in Amps) from the CT at 100%
load.
C) Follow the line for the CT current to where the
gradient on the x-axis cuts the line.
D) Check the resistance value (in Ohms) on the y-axis
for this point. This is the total resistance value over
terminals 5 – 5 (meaning the resistance of the hea-
ting element in parallel with the matching resistance)
(refer to chapter 8.6, Figure 14).
E) Connect an Ohm-meter to terminals 5 – 5 and adjust
the Matching Resistance MRB110-1 or MRB110-2
until the determined resistance value is reached.
Secure the lock-nut to this value.
F) With this setting you should reach the required
gradient for the 100% CT current you have chosen.
G) To verify the setting, please feed a stable current
(AC or DC) equivalent to the 100% CT current to
the terminals 5 – 5, keep the instrument cover on
the instrument and wait 45 minutes before verifying
the reading and the achieved temperature gradient.
If adjustments of the gradient are necessary please
adjust:
a. towards a higher resistance value to get a higher
gradient
b. towards a lower resistance value to get a lower
gradient
H) For more details please also refer to chapter 6.1.
Fig. 8
Temperature gradient graph for bulb types 1, 2, 2F, 5, 8, 22, 27 and measuring ranges
0...150 °C and -20...130 °C