Powtier Controls Limited
505MST Thermostat
Instruction Manual
Termate M4 stud terminals are used; these have a voltage clearance of 20mm and 25mm
creepage distance and is suitable for 415Vac switching.
Non-metallic fixings are used on the terminal to meet the voltage clearance requirement.
Sensor connection
The saloon sensor, external to the thermostat unit, has three wire connections, a screen (green)
and two sensor wires (red and blue). It is supplied with 250mm of screen cable, type BR Cat.
No. 6/146700.
The green wire is to be connected to the M4 stud terminal marked "SCREEN" inside the
thermostat unit; the two sensor wires (red and blue) can to be connected in any order to the
M4 terminal marked "0V" and "SALOON" (the PT100 sensor is a passive resistive device and
has no polarity).
The other sensor, which senses the ambient temperature, is factory fixed inside the thermostat
unit.
Sensor terminal
Terminals
Descriptions
SALOON
Saloon air sensor (to be connected)
0V
Supply 0Vdc terminal
SCREEN
Sensor screens
A 3-way Termate M4 stud terminals are used for the connections of the saloon sensor.
Diagnostic Test socket
Terminals
Descriptions
SALOON
Saloon air sensor
0V
Common returns from sensor and supply
20Vdc
Supply to TC1005 test equipment
A 5-way Litton rear-panel mounted receptacle is fitted to the thermostat unit.
Test and calibration
The 505MST/M thermostat units can be tested and calibrated on site with a dedicated Test
and Calibration unit, model TC1000.
The TC1000 unit consists of a LCD display, a 10-turns potentiometer and one switch.
Connection of the unit to the system is made via a 5-way connector. The TC1000 comes with
its own carrying case.
The TC1000 unit's LCD display two different temperatures: the saloon sensor temperature and
the saloon simulated test temperature.
505MSTIM
Page 8
29 June 1998
Issue 1.0
