HF scientific Oil Content Monitor - Manual (Page 10)

OCM Rev. 3.9 (1/03) 4
3.3.1 Power Source
The power source required is 90 – 250VAC, 47-90Hz. The power consumption is 6VA.
Connections are made at the far right hand terminals.
Please observe safe wiring practices. It is recommended that a circuit breaker or switch
be placed prior to the power connection to the OCM to allow for service.
Note: Only qualified electricians should be allowed to perform the installation of the
instrument as it involves a line voltage that could endanger life.
3.3.2 Relay Connections
Relay connections for Alarm 1 and Alarm 2 are located next to the power connection.
These relays are rated at 120-240VAC 2A for the mechanical. The optional solid state
relays are rated at 120-240VAC 1A.
The Sensor Alarm connection is located to the left of Alarm 1. This relay is rated for up
to 30VDC 2A.
3.3.3 4-20 mA Output
A 4-20 mA signal is provided. This output is referenced to the scale of 0-30 PPM as set at
the factory but may be set to any portion of the scale of 0-50 PPM. Connections for the 4-
20 mA are located next to the Sensor Alarm.
3.3.4 Unused Terminals
Located next to the 4-20mA outputs are some terminals that are not used in this
instrument. These terminals are not connected inside the instrument and cannot be used.
3.4.5 Cabinet
Integrity
To maintain the seal of the field terminal box, it is important to use suitable size cable
through the compression fittings. If suitable size cable is not available, use vinyl tubing or
electrical tape to make up the difference. Tighten all compression fittings by hand. Do not
remove the plastic dowel plugs in unused fittings as these serve to complete the cabinet
seal. When closing the lid, ensure that no wires are pinched and that the o-ring is in good
condition. Tighten the four corner screws firmly.