BENDIX BW1450 manual Unloaded for a minimum of 30 seconds. This

AD-4™AIR DRYER TROUBLESHOOTING CHART (Continued)

SYMPTOMS	CAUSE	REMEDY
2. Water and/or Oil in	C. Air dryer not purging	C. See Symptom #5.
Supply or Service	(see Symptom #5).
Reservoir (continued).
	D. Purge (air exhaust) time	D. Check causes and remedies for Symptom #1.
	insufficient due to
	excessive system
	leakage (see causes for
	Symptom #1).
	E. Excessive air usage,	E. See Appendix A, Table A, column 1, for
	duty cycle too high - Air	recommended compressor sizes. If the
	dryer not compatible	compressor is “too small” for the vehicle vocation
	with vehicle air system	(for example, where a vehicle’s vocation has
	requirement (Improper air	changed or service conditions exceed the original
	dryer/vehicle	vehicle or engine OE spec’s) then upgrade the
	application).	compressor. Note: The costs incurred (e.g.
	NOTE: Duty Cycle is the	installing a larger capacity compressor, etc.) are
		not covered under original compressor warranty.
	ratio of time the compressor
	spends building air to total	Charge Cycle Time - The AD-4™air dryer is
	engine running time. Air	designed to provide clean, dry air for the brake
	compressors are designed	system. When a vehicle’s air system is used to
	to build air (run “loaded”) up	operate non-brake air accessories it is necessary
	to 25% of the time. Higher	to determine that; during normal, daily operation
	duty cycles cause	the compressor should recover from governor
	conditions that affect air	“cut-in” to governor “cut-out” (usually 100 psi to
	brake charging system	120 psi) in 90 seconds or less at engine RPM’s
	performance which may	commensurate with the vehicle vocation. If the
	require additional	recovery time consistently exceeds this limit, it
	maintenance. Factors that	may be necessary to “bypass” the air accessory
	add to the duty cycle are: air	responsible for the high air usage. An example of
	suspension, additional air	where a by-pass system would be required is
	accessories, use of an	when the compressor is used to pressurize a
	undersized compressor,	tank trailer for purposes of off-loading product.
	frequent stops, excessive	Consult your local authorized Bendix parts outlet
	leakage from fittings,	or sales representative for additional information.
	connections, lines,	Purge Cycle Time - During normal vehicle
	chambers or valves, etc.
		operation, the air compressor must remain
		unloaded for a minimum of 30 seconds. This
		minimum purge time is required to ensure
		complete regeneration of the desiccant material.
		If the purge time is consistently less than the
		minimum, an accessory by-pass system must be
		installed. Consult your local authorized Bendix
		parts outlet or sales representative for additional
		information.
		Air Compressor Size - Although the AD-4™air
		dryer can be used in conjunction with larger
		compressors, it was designed primarily for units
		rated for up to 30 CFM. It is recommended that
		when using the AD-4™air dryer with a
		compressor which has a rated displacement
		exceeding 30 CFM that an authorized Bendix
		parts outlet or Bendix marketing representative
		be contacted for assistance.

17