User manual ROTOTHERM RTH TEMPERATURE & HUMIDITY RECORDER

[. . . ] Expansion, or contraction, of the bimetallic coil, due to temperature change causes pen movement by direct linkage. Similarly, a change in humidity causes extension or contraction of the hygroscopic membrane and direct linkage again causes movement of the second pen. The RTH100 Series range comprises of recorders and recorder controllers as either temperature, humidity or combination instruments. Controllers can be supplied with up to four separate alarm contacts set by reference to a setting pointer adjustable over the full chart range. [. . . ] This alarm may be silenced in one of two ways according to the setting of the mode switch which is located on the relay printed circuit board beneath the chart plate. In Mode 1 the alarm will be permanently silenced when the light-emitting diode (LED) built into the mute switch is illuminated. When not silenced, the audible alarm will sound for as long as the pen remains outside the contact limits. In Mode 2 an audible alarm caused by either pen moving outside the contact limits may be silenced temporarily by pressing the mute push-button. The mute switch LED will be illuminated to acknowledge that the alarm has been silenced. The alarm will only be silenced while the pen remains outside contact limits: the temporary silence will be cancelled automatically when the pen returns to within limits and the alarm will sound again should the pen subsequently move outside limits once more. If an alarm caused by one of the two pens is temporarily silenced, the second pen will still cause the alarm to sound if it too also moves outside its contact limits. Pressing the mute push button once more will silence the second alarm. Installation Ideally the site chosen should be free from dust, corrosive fumes, vibration and extremes of temperature. Mounting the Controller The controller may be surface or flush panel mounted. For surface mounting, remove the screws holding the three brackets at the rear of the case, reverse and refit brackets with there ends projecting from the edges of the case. Drill three holes in the panel (or wall), of the size and at the centres given in Fig. Locate the instrument on this screw and fit two similar screws through the other two brackets to secure. For flush panel mounting, make a cut out to the dimensions given in Fig. Remove the nuts and washers from the studs projecting from behind the case flange, pass the instrument through the cut-out and refit the washers and nuts to secure the instrument. 3 RTH100 Series Temperature & Humidity Recorder Instruction Manual Page 4 Portable Mounting Surface Mounting Flush Panel Mounting All dimensions are in mm Fig 2. Outline Dimensions and Fixing Details 4 RTH100 Series Temperature & Humidity Recorder Instruction Manual Page 5 Access to Instrument To open the instrument door press the plunger of the door lock and pull the door forward from the right. As the door is opened the pen lifter raises the pen ( or pens) away from the chart. Remove the thread that secures the pens to the pen lifter for transit purposes. To make electrical connections and to set contacts remove the chart plate by loosening the three retaining screws and carefully lift out the chart plate via the finger hole ( care is necessary to avoid pen lifter interference with pens and control pointers ). Pull the bottom edge clear of the instrument and lower the chart plate from behind the pens. If the instrument already has a chart fitted this will need to be removed ( see Fig. 4. ). Electrical Connections BEFORE MAKING ANY CONNECTIONS TO THE INSTRUMENT ENSURE MAINS SUPPLY CABLE HAS BEEN ISOLATED FROM THE MAINS SUPPLY All electrical connections are made to terminal blocks in the lower part of the case behind the chart plate. Mains Supply and Relay Connections Insert mains supply cable (isolated) through cable gland in the underside of the case and connect to either the stand alone terminal block for recorders or the power supply board terminal block for controllers. [. . . ] With the chart plate removed, cut a segment of chart and place on to the chart clamp. Set the desired value pointer (1 or 2) to the required value by means of the setting knob (3 or 4). Move the actual value pen (5 or 6) until it just makes contact with the switch arm (7). Note: The contact point can be determined by observing the LED's in the instrument door The mains supply needs to be connected and switched on and the insulation spanner supplied must be used (the mechanism contacts carry 12 volts). Move the actual value pen (5 or 6) to the required deviation above the desired value pointer (1 or 2) and adjust the high contact (9 or 10) until it just makes contact with the switch arm (7) as indicated by the high alarm LED in the instrument door. [. . . ]