Ulvac G-100D - Operation in Cold Climates; Backflow Preventer(G-100 S); Thermal Protector

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4.4 Operation in cold climates
When using the pump in winter, in cold climates, or outdoors, it is sometimes difficult to start
the pump. This is an overload phenomenon resulting from the increase in the viscosity of the
pump oil. To start the pump in such conditions, warm up the pump oil, or turn the pump on and
off several times in short intervals.
When the pump stops after rotating for a few seconds, open leak valve (B) and continuous
operation may become possible. After the pump has warmed up, close leak valve (B) and return
to ordinary operation.
4.5 Backflow preventer(G-100S)
A backflow preventer is incorporated into the pump to prevent the oil from flowing back while
the pump is stopped.
The backflow preventer actuates in the case of an emergency including power failure. So, after
the pump is stopped due to a power failure, follow the procedures mentioned in “4.3 Stopping
the operation” to stop the operation.
① To stop the pump, always close vacuum valve (A) and then open leak valve
(B). If this procedure is neglected, the pump oil fills the cylinder,
making restart difficult or causing damage to the pump. The pump oil also
may flow back to the vacuum chamber side.
② If vacuum valve (A) is not closed, air may leak into the device side through
the pump increasing the pressure.
4.6 Thermal protector
A manually reset thermal protector is incorporated in the motor in order to interrupt the power
circuit of the motor and prevent damage to the motor when an over current flows through the
motor due to a stop in rotation or overload resulting from the pump malfunctioning during
operation. The type of thermal protector to be used depends on the pump model.
Table 3 Characteristics of the thermal protector
Model
Operating characteristic
50Hz 60Hz
G-100D,G-100S
1φ,100V
34.5(A) at25℃ 34.5(A) at25℃
1φ,115V
33.0(A) at25℃ 32.0(A) at25℃
1φ,200V
18.5(A) at20℃ 18.5(A) at20℃
1φ,220V
17.0(A) at25℃ 17.0(A) at25℃
1φ,230V
17.3(A) at25℃ 16.7(A) at25℃
When the thermal protector has been actuated, turn off the switch and contact us.
The motor is very hot when the thermal protector has actuated. Never touch it with your hand.
When the cause of the malfunction has been eliminated, check that the motor has cooled down,
and then press the manual reset button to restart operation (see “6.5 Trouble check list”).
Note