TM 5-3895-374-24-2 Step 8. LOW OIL LEVEL SWITCH A  float  activated  switch  is  installed   to   protect   your compressor against damage due to insufficient oil level. The switch operates on a fail-safe principle and is mechanically actuated for sealed, friction-less operation.  Low oil level in the frames causes the switch contacts to open, thus shutting   the   unit   down   until   the   proper   oil   level   has   been restored. The  Low  Oil  Level  Switch  is  a  single  pole,  double throw snap switch,   available   with   a   NEMA   1   enclosure. (An  optional  NEMA  7  enclosure  is  available).    (See  Wiring Diagram   on   Page   24   for   connection   of   the   Low   Oil   Level Switch.) NEMA  1  ENCLOSURE:  This  switch  has  a  maximum rating of 5 amps at 125,250 or 480 volt operation and uses a %" nominal size flexible steel conduit, of a length as required, over the switch lead wires. The   switch   is   not   acceptable   for greater than 480 volts. (Optional)  NEMA  7  ENCLOSURE:  This  switch  has  a maximum   rating   of   4   amps   at   250   volt   operation   and   is equipped with a 2 1/2" NPT non-removable fitting. WARNING Proper  protection  against  low  oil  levels  depends  on proper adjustment of the low oil level switch. During the initial run, stop unit and drain one quart of oil from crankcase into clean can, and listen for switch to click or check with continuity tester. This  is  a  "float"  type  switch  which  sometimes  gets cocked   in   shipping.      If   cocked   or   stuck,   open   disconnect switch, drain remaining oil, remove crankcase cover and then free the float.  Reassemble and then reuse the same oil. NOTE If   float   is   cocked   in   the   low   position, compressor cannot start. Step 9 DISCHARGE PIPING The   following   general   instructions   cover   only   the installation of discharge piping and placement of safety valves, pressure switch, pressure gauge, auxiliary valve, drain valves, shut-off   valves, etc.   in   systems   using   a   detached   receiver. See Figure 2-3.  Discharge piping should be the same size as the compressor discharge connection or the receiver discharge connection( All pipe   and   fittings   must   be   certified   safe   for   the   pressures involved.  Pipe thread sealant is to be used on all threads, and all  joints  are  to  be  made  up  tightly,  since  small  leaks  in  the discharge    system    are    the    largest    single    cause    of    high operating   costs.      If   your   compressor   runs   more   than   you believe  it  should,  the  most  likely  cause  is  a  leaky  pipe  line. Leaks are easily located by squirting soap and water  solution around the joints and watching for bubbles. When a baseplate mounted unit or a bare compressor  is  supplied,  it  is  very  important  to   observe   the following    points    when    installing    the    piping    between    the compressor and the receiver. WARNING 1. If possible, run the piping down from the compressor discharge  to  permit  the  condensate  to  drain  into  the receiver.  If this is not possible, Install a "drain leg" as shown  in  Figure  2-3.    The  drain  leg  should  project down from the compressor discharge and be at least 10" (254 mm) long. 2. Put a drain valve at the end of this pipe and drain at least weekly, or as often as necessary. Figure 2-3.  Typical piping arrangement for compressor and detached receiver. The  length  of  the  tube  line  connecting  the  auxiliary valve  will  have  a  bearing  on  the  operation  of  the  regulation system.    For  lengths  up  to  12  feet  (3.6  m),  use  5/16  O.D. copper  tubing  that  has  been  certified  safe  for  the  pressures involved.  For lengths over 12 feet (3.6 m), use the next larger size copper tubing that is certified safe for pressures involved, or contact your nearest I-R distributor. Step 10. COMPLETE WARRANTY REGISTRATION Completion of the registration form indicates satisfactory installation and performance of start-up operations.   If   any   defects   are   apparent   in   the   equipment; contact  the  nearest  I-R  Distributor  or  Ingersoll-Rand  District office.    The  I-R  service  literature  included  with  the  unit  has instructions for minor adjustments.  Minor adjustments are not considered warranty. page 3-833 Hazardous voltage. Connecting  pressure  switch  or  low  oil  level switch   directly   to   motor   can   cause   severe injury or death. Always  insure  the  pressure  switch  or  low  oil level   switch   is   connected   thru   the   control circuit of a magnetic starter. This machine contains high pressure air.  Can cause eye injury or death from flying parts. If  an  after  cooler,  check  valve,  block  valve  or any other restriction is added to the compressor   discharge   and   ASME   approved safety   valve   must   be   installed   between   the compressor discharge and the restriction.