PTR 225 / PTR 225 S PTR 237 - Schoonover, Inc.

2.2.1 Power Supply
Warning The PENNING transmitter PTR 225,
PTR 225 S or PTR 237 may only be
connected to supply units or measuring
instruments which meet the requirements
of mains isolated extra-low voltages
(PELV) and VDE 0100.
The PENNING transmitter PTR 225, PTR 225 S or PTR
237 is capable of operating off supply voltages ranging
from 14.5 V to 36 V. A supply voltage of 24 V DC is
recommended.
The power supply must be connected to Pin 1 (+) and
Pin 2 (power supply ground).
2.2.2 Switching on the High Tension
The high voltage may be switched on either through Pin
7 using negative logic or Pin 8 using positive logic.
Note
Switching on via Pin 8 is only possible from Serial Number
D 95 11 01000 onwards.
In each case Pin 2 must be used as the reference potential.
Pin 7 switches the high voltage on when
- contact is established with Pin 2 or
- a voltage of less than 2.5 V is present with reference to
Pin 2.
Pin 7 switches the high voltage off when
- there is no contact with Pin 2 (open input) or
- a voltage greater than 4 V is present with reference to
Pin 2.
Pin 8 switches the high voltage on when
- contact is established with Pin 1 (supply voltage) or
- a voltage greater than 12 V is present with reference to
Pin 2.
Pin 8 switches the high voltage off when
- there is no contact with Pin 1 (open input) or
- a voltage of less than 7 V is present with reference to
Pin 2.
Operation of the PTR 225, PTR 225 S or PTR 237 in the
pressure range above 10 -2 mbar will cause the accumulation
of contaminations and will thus reduce service life.
For this reason, the high tension should only be switched
on or off when the pressure has dropped to the 10 -2 to
10 -3 mbar range.
The high tension may also be switched on or off directly
by the output signal provided by a THERMOVAC TTR
211 S / TTR 216 S transmitter. Thus the PENNING transmitter
can be switched on or off automatically at a pressure
of approximately 5·10 -3 mbar.
12 GA 09.308/4.02 - 05/97
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