LEYBOLD THERMOVAC TTR 101 N, Operating Manual, Page: 15 / 42

15 300544655_002_C1 - 11/2016 - © Leybold
Transmitter Installation (Electrical)
TTR 101 N THERMOVAC transmitters are available with different input/output connectors. Use a cable with strain
relief to ensure proper electrical connection and to reduce stress on the connectors.
To comply with EN61326-1 immunity requirements, use a braided shielded cable. Connect the braid to the metal
hoods at both ends of the cable with the end for power supply connected to earth ground.
Ground loops, differences of potential, or EMC problems may affect the measurement signal. For optimum signal
quality, please do observe the following notes:

Use an overall metal braided shielded cable. The connector must have a metal case.

Connect the cable shield to ground at one side via the connector case. Make sure the connector case has
direct contact to the cable's shield on its whole circumference. Do not connect the other side of the shield.

Connect the supply common with protective ground directly at the power.

Use differential measurement input (signal common and supply common conducted separately).

Potential difference between supply common and housing ≤18 V (overvoltage protection).
The power supply input is 9 to 30 VDC. The power supply input is protected by an internal thermal fuse. The fuse is
self-recoverable; do not replace it. Damage may occur to the circuitry if excessive voltage is applied, polarity
reversed or if a wrong connection is made.
If using the analog voltage output, connect the positive analog out and negative analog out pins to a differential
input voltmeter or an analog-to-digital (A/D) converter. Do not connect the negative side of the analog output to the
negative side of the power supply input or to any other ground. Doing so will cause half of the power current to flow
through this wire. Measurement errors in the output voltage may be seen due to the voltage drop from this current.
The longer the cable, the worse the error will be. Do not connect the set point relay terminals to the analog output.
Correct connection of analog output to floating input
Incorrect connection of analog output to non-floating input
Ensure a low impedance electrical connection between the transmitter body and the grounded
vacuum system to shield the sensor from external electromagnetic sources.
Ensure that the analog output is connected to floating input.
Attention
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