
3 Installation
3.5 Electrical installation
DB1 variable frequency drive
11/20 MN040031EN
Eaton.com
73
3.5.3 Thermistor connection
As a way of protecting against thermal overload in the motor, motor thermis-
tors and motor temperature switches (Thermo-Click) can be connected to
control signal terminal 4 (DI3 = digital input 3).
In this case, parameter P-15 must be used to select the EXTFLT
(external fault) setting for DI3, and parameter P-47 must be set to a value of
6 (
Ptc-th
).
Figure 43: Thermistor connection
The thermistors and temperature switches used must be PTC-type units
(PTC characteristic, positive temperature coefficient).
These are triggered as a resistance value of approx. 2.5 k
Ω
- 3 k
Ω
, and a
reset is triggered at approx.1.9 k
Ω
- 1 k
Ω
.
T1
T2
M 3 ∼
Thermoclick sensor
ϑ
ϑ
U
V
W
PE
PTC type
≧ 2.5 kΩ trip level
≦ 1.9 kΩ Reset
PES
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