0 installation – ENMET ISA-RAL-M User Manual

Page 9

ISA-RAL-M, ISA-RAH-M

ENMET Corporation

4.0 Installation

After becoming familiar with the main parts and their functions, follow the installation procedure as outlined below.

AUTION

Neither the ISA-RAL-M control unit nor its sensor are rated for explosionproof environments. Take

caution that neither one is installed in an explosionproof-rated area.

1. Choose an appropriate location for mounting the electronics control unit and sample head assembly. The

mounting dimensions are given in Figure 1. Locate the sampling point upstream from the workers such that the
respiratory air reaches the carbon monoxide sensor before it reaches the workers. Locate the control unit, or an
auxiliary visual alarm actuated by the instrument's relay contacts, in an area where it can easily be seen by
workers using the breathing air.

OTE

: That the flow rate of the sample air to the sensor head is approximately

SCFH

(Standard Cubic Feet per Hour).

2. A 110 Vac line cord is supplied, plug this into an appropriate outlet.

3. If conduit is preferred, remove the terminal strip cover from TB4 inside the control unit (simply pull the cover off

its holding prongs). Apply 110 Vac power to the appropriate terminals. Refer to Figure 5.

OTE

Utilizing 220 Vac power requires a change in the transformer hook-up by a competent electrician or

electronics technician; but this change is best done at ENMET. 12 Vdc may be used as a primary source (refer
to Figure 5) or as an emergency back-up power source, both ac and dc power can be applied at the same time.
Current flows from the ac source; dc current will flow only when the ac power is interrupted.

4. Run the relay contact leads through the same oiltight fitting as the power supply leads or out through a second fitting.

OTE

When the power supply is interrupted, the relays switch to the same position as for a true gas alarm condition,

and the power light goes off. Do not connect the unit to other voltage supply lines.
The ISA-RAL-M is completely oiltight. Use the correct oiltight fitting for the cord or conduit when supplying
power to the unit.