4
piping is supported. Do not allow the weight of any pip-
ing to bear on the dryer or filters. Piping should be the
same size as or larger than the dryer connection. Piping
smaller than the dryer connections will cause high pres-
sure drop and reduce drying capacity.
If the purge exhaust piping must be extended outside the
dryer area, choose a combination of diameters, lengths,
and turns that limits the additional pressure drop to 1/4
psid or less.
BACK PRESSURE WILL CAUSE DRYER
MALFUNCTION.
Consult the factory for piping details
if required.
WARNING — Do not operate dryer without installed
mufflers. Exhausting compressed air directly to
atmosphere will result in noise levels above OSHA
permissible levels and rapidly expanding gas could
potentially cause harm to persons or property.
Dryer bypass piping may be installed to allow uninter-
rupted airflow during servicing. If the downstream appli-
cation cannot tolerate unprocessed air for short periods,
install a second dryer in the bypass line.
CAUTION — Do not hydrostatically test the piping
with the dryer in the system. The desiccant will be
damaged if saturated with water.
4.5 Electrical Connections
WARNING — These procedures require entering
gaining access to the dryer’s electrical enclosure(s).
All electrical work must be performed by a qualified
electrical technician.
Connect the proper power supply to the dryer according
to the electrical drawings in the back of this manual. Be
sure to follow all applicable electrical codes.
NOTE:
A disconnect switch is not provided as standard
equipment and therefore, must be supplied by the cus-
tomer.
Dry contacts (voltage free) are provided in the low ten-
sion electrical enclosure for a remote alarm. The contact
ratings are shown on the electrical drawing.
Compressor
Aftercooler
Separator
Receiver
Prefilters
Afterfilters
Receiver
Desiccant Dryer
Figure 1
Typical System Configuration
Connections to voltage-free common alarm contacts
with a minimum 5-amp rating can be made at terminals
TB4-1 through 3.
• Terminal TB4-3 is the common alarm connection.
• Terminal TB4-1 is the N.O.. (normally open) contact
connection.
• Terminal TB4-2 is the N.C. (normally closed) contact
connection.
• The alarm relay coil is energized when power is
supplied to the controller input terminals and there
is no alarms.
• The coil is de-energized when power is removed or
when an alarm condition exists.
NOTE:
Before turning high voltage on to the dryer, an
ohmic test should be performed on the heater elements
to insure they are dry before proceeding with start-up.
This should be done after extended shut downs and long
delays between delivery and start-up. Connect one lead
of a megger to an unpainted surface of the control panel
or dryer frame. Connect the other lead to each phase
on the load side of the contactor. Adjust the megger to
the 1500 volt setting. Perform the ohmic test on each
zone of the heaters. A minimum value of 500k ohms
must be obtained.
CAUTION - Failure to ohmic test heaters after ex-
tended periods may cause heater failure.
4.5.1 RS-232 Connections
RS-232 connections can be made at the 3-pin connector
labeled J3 and located at the upper left-handed corner
of the control board. A cable for this connection can be
purchased through your distributor.
4.6 Initial Desiccant Charge
Blower purge type regenerative dryers use activated
alumina as the desiccant in the dryer towers.
Models 500 through 1050 are shipped with activated
alumina (1/8” bead) in the dryer towers. Desiccant is
shipped loose with all other standard models.
Summary of Contents for HBP Series
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