C.M.C. n.v. - Airmaster S1 installation guide – V1.2 – MANY0402A.00
6.4.1 The emergency stop contact input
The contact, which is connected between the first digital input and the common digital
inputs supply terminal, is also feeding the internal relays of the Airmaster S1. As soon
as this contact opens, all relays are de-energized. In this manner, when an emergency
occurs, all outputs become non-active without intervention of the microprocessor or
software. This contact must be normal-closed, which opens in case of emergency stop.
Contactors, relays or other output devices connected to the
relay outputs of the Airmaster S1 must also be disconnected by
another contact on the emergency stop button.
Special precautions must be foreseen that no over voltage is
applied to the emergency stop contact input.
6.4.2 The contact inputs
The Airmaster S1 can read the status of all contact inputs. Over an open contact a
minimum voltage of 18Vdc is maintained. When the external contact is closed a
minimum current of 5mA runs through the contact. This is intended to prevent contact
oxidization errors.
6.4.3 The PTC input
The last contact input can be used to indicate the status of a Positive Temperature
Coefficient thermistor (PTC). The characteristic of the input is according to IEC 34-11-2,
VDE 0660.
Do not apply an external voltage on the PTC input, as
this will damage the unit.
The PTC input can also be used for switching contact inputs. If used in this way
attention to the type of contact must be made, as the closed circuit current is low and
may not penetrate oxidization. Use with gold flashed contacts in enclosed or sealed
devices.
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