D
US
© Danfoss | Climate Solutions | 2023.09
AQ450437934291en-US0301 | 21
Relay position INT69 G
B2
12
14
11
Fig. 16
5
|
Electrical connection
Gauge state
Relay position
1.
Deactivated state
11-12
2.
INT69 G switch-on
11-14
3.
Remove PTC connector
11-12
4.
Insert PTC connector
11-12
5.
Reset after mains on
11-14
5.7 Oil sump heater
In order to avoid damage to the compressor, the compressor is equipped with an oil sump heater as
a standard feature.
Operation:
The oil sump heater operates when the compressor is at a standstill.
When the compressor starts up, the oil sump heating switches off.
Connection:
The oil sump heater must be connected via an auxiliary contact (or parallel wired auxiliary
contact) of the compressor contactor to a separate electric circuit
.
Electrical data: 115 V - 1 - 60 Hz, 80 W.
The oil sump heater must generally be connected and operated!
5.8 Selection and operation of compressors with frequency converters
For safe operation of the compressor, the frequency converter must be able to apply an overload of
at least 160% of the compressor's maximum current (I-max.) for at least 3 seconds.
When using frequency converters, the following things must also be observed:
1. The maximum permissible operating current of the compressor (I-max) (see type plate or
technical data) must not be exceeded.
2. If abnormal vibrations occur in the system, the affected frequency ranges in the frequency
converter must be blanked out accordingly.
3. The maximum output current of the frequency converter must be greater than the maximum
current of the compressor (I-max).
4. After each compressor start, run for at least 1 minute at a frequency of at least 50 Hz.
5. Carry out all designs and installations in accordance with the local safety regulations and
common rules (e.g. VDE) and regulations as well as in accordance with the specifications of the
frequency converter manufacturer
The permissible frequency range can be found in the technical data.
For compressors with LSPM motors,
operation with frequency converter is only recommended
in delta connection with corner point of the V/f curve 277 V / 60 Hz. This ensures that during
operation of the compressor, within the permissible frequency band and application limits, the
motor does not fall into its asynchronous state due to undervoltage/field weakening operation.
For start-up and low speed operation, a voltage boost of 10-20 V is recommended to slightly reduce
the motor current and compensate for voltage drops through the compressor supply line (and filtering
devices, if present).
