Parallax Power Supply ALS 20 User manual

GENERAL INFORMATION
The Parallax Power Supply ALS 20 automatic load shed is designed to
automatically switch off a secondary load in a high current situation. This allows
for the connection of two high current devices to a single 20-amp breaker. Often,
the job of the ALS 20 has been performed by a manual device selector switch.
Typically the ALS 20 will be configured so that when the on demand current is at a
very high level the ALS 20 will automatically shed, or disconnect a secondary load
such as a water heater whose operation can be temporarily postponed without
directly affecting the user. This situation would normally occur by activating a high
current on-demand device such as a microwave or hair dryer. In addition the ALS
20 may also be installed to allow for the operation of more than 2 thermostatically
controlled devices on a 120V 30AMP service, as per the NEC 551-42(c). After the
current demands drop on the circuit, and a short safety delay the ALS 20 will
automatically switch the disconnected load back on.
Refer installation and servicing of this product to qualified service personnel.
Technical or service information is provided solely for use by licensed
electricians and certified RV technicians. No endorsement of technical expertise
is expressed and/or implied. User assumes all liabilities arising from use of this
information.
OPERATION
After the ALS 20 unit is installed, using one of the typical installations shown in this
manual, it will be ready for years of trouble-free service. Operation is automatic and
no maintenance is required.
TYPICAL INSTALLATIONS
WIRING INSTRUCTIONS
CAUTION:
Observe the polarity and torque specifications per the installation label included
on the inside cover of each unit.

MOUNTING LOCATION
The ALS 20 is designed for indoor use only.
DO NOT mount in harsh environments; avoid areas where high levels of dust, dirt,
or moisture may occur.
DO NOT mount in the same compartment as batteries or other flammable materials
such as gasoline.
The ALS 20 maybe mounted in any position, leaving room forrouting input and load
conductors.
Mounting requirements: 4 surface-appropriate fasteners for the 4 holes provided in
the flanges.
SPECIFICATIONS
(Subject to change without prior notice)
Electrical rating: 120VAC, 20 amp
Relay: DPDT rated 30-amp
Coil: 110VDC
Input: 120VAC, 20 amp protected branch circuit.
Priority load circuit: 120VAC, 20 amp MAX.
Shed load circuit: 120VAC, 18 amp MAX.
Dimensions:
Width: 4.75”
Height: 4.125”
Length: 6.250”
Mounting Baseplate:
Width: 6.00”
Length: 6.25”
Weight: 3.75 pounds (all models)
Not ignition protected
WARRANTY INFORMATION
Reference the enclosed Parallax Power Supply Warranty Policy or download the
policy at: http://www.parallaxpower.com/warranty
Parallax Power Supply
Phone: [phone] •Fax: [phone]
Powering the RV Adventure
ALS 20 AUTOMATIC LOAD SHED
OWNER OPERATION GUIDE
Visit our website at www.parallaxpower.com
Congratulations on the purchase of your new Parallax Power Supply
product!
The Parallax ALS 20 automatic load shed have been designed to give
safe, reliable, and maintenance-free service.
We hope it provides many years of enjoyment.
011-0200-003 Rev C
Listed for RV use in the U.S.A. and Canada