Operation 3 - 5
right chamber. Both Purge Exhaust Switching
Valves will close. The desiccant chambers will im-
mediately begin pressurizing to system pressure as
indicated by chamber pressure gauges.
10. The Moisture Indicator’s (if dryer so-equipped) bleed
valve is installed directly into the back of the
indicator’s body. Close the Indicator’s Bleed Valve.
FULLY open the Moisture Indicator Supply Valve.
11. Soap bubble test all external piping, fittings, and con-
nections. Locate and repair all noted points of leak-
age. Do not soap bubble test components lo-
cated inside dryer control system's enclosure.
Note: Small leaks noted in inlet piping to the dryer
will not affect operation, other than a slight loss of
pressure supplied to the dryer. HOWEVER, any gas
leaks, (no matter how small), detected at, or down-
stream of the dryer outlet MUST BE FIXED to ensure
that the dryer will provide a continuous supply of pro-
cess gas at specified dew point, to intended points-
of-use.
IMPORTANT: Water molecules can diffuse through
a pinhole-size leak even though pressure inside the
piping is several hundred PSIG. It is not uncommon
to have a minute pinhole leak in a gas line cause an
increase in dew point from -40°F to -10°F at a dis-
tance of forty or more feet downstream of the leak.
12. SLOWLY open the System Outlet Isolation Valve
(customer supplied), while monitoring the Outlet
Pressure Gauge (if dryer so-equipped). DO NOT per-
mit the Dryer's Outlet Pressure Gauge to exceed a
5% drop in pressure while pressurizing downstream
piping.
13. Close the System Bypass Valve (if gas system has
been so-equipped).
14. Open and adjust the Moisture Indicator’s Bleed Valve
until a very slight, continuous gas bleed is felt ex-
hausting from the bleed valve’s exhaust port. Ensure
that the granular indicator crystals remain motionless
after final adjustment.
15. Energize the dryer’s electrical power supply.
16. Refer to Appendix A (Appendix C for -100°F pdp) of
this manual and calculate your dryer model's purge
pressure setting as instructed.
17. Locate the Purge Adjusting Valve. Slowly rotate
dryer’s Purge Adjusting Valve until the Purge Pres-
sure Indicator indicates the calculated purge pressure
setting. (See following Note).
Note: The purge pressure can only be read and ad-
justed when an off-stream desiccant chamber has
depressurized for regeneration. (When the off-
stream chamber is pressurized, the Purge Pressure
Indicator will read “system pressure”.)
For dryers with the Hydrobloc Energy Management
System: During operation in the Energy Manage-
ment Mode, the off-stream chamber may remain
pressurized (in ENERGY MANAGEMENT ACTIVE).
If this condition is noted, proceed as follows to adjust
purge pressure.
a) Open Dryer Control System Enclosure. Locate
DIP switches on MEC CPU Board.
b) Switch DIP switch position 7 to OFF position
(down). De-energize dryer’s electrical power sup-
ply for approximately fifteen (15) seconds; then
re-energize. Dryer is now in Fixed Cycle Opera-
tion. The off-stream chamber will depressurize to
atmosphere for regeneration.
c) Calculate and set purge pressure as previously
instructed.
d) Return DIP switch position 7 to ON position.
De-energize the dryer’s electrical power supply
for approximately fifteen (15) seconds; then re-
energize. Dryer should be in Compu-Save En-
ergy Saver Mode.
18. The Start-Up procedure for models LS1250 and
LS1500 is now complete. Proceed to the Normal Op-
eration Checks section of this manual for final opera-
tional checks and adjustments.
Dryer Models LS2070 and LS2580
Do not start the dryer with compressed air flow through
the dryer. Close customer supplied dryer shut-off valves
before beginning start-up procedure.
1. Refer to the General Arrangement drawing as neces-
sary for component identification and location while
conducting start-up and operational procedures.
Note: If your dryer cannot be started, or fails to start
due to special installation or other problems, contact
your local Deltech Sales Representative for assis-
tance.
2. Remove the Pilot Gas Filter Bowl. Verify that the pi-
lot gas filter cartridge is installed. Replace Filter
Bowl ensuring that O-ring is properly seated. Close
the filter bowl bleed valve.
3. All Prefilter and Afterfilter Assemblies are shipped
WITH filter cartridges installed. Verify that prefilter
and afterfilter cartridges are installed. Prefilter and
Afterfilter cartridges are NOT interchangeable and
must be installed in their respective assemblies
ONLY. The proper filter cartridge part number is
listed on each Prefilter and Afterfilter Assembly.
4. Replace and tighten filter assembly bowls. Ensure
that O-rings are properly seated.