E) Current Limit Circuit; H) High Temperature Output Reduction Circuit; Vi) Troubleshooting - NewMar PT-24-45W Bb8Db2Cc8C9B8A4Bb2Bbe763F

continuous operation at full rating, the Phase Three chargers
employ multiple integral cooling fans. Whenever load and/or
ambient temperature cause a significant rise in the internal
temperature, these fans will adjust automatically or cycle on
and off, as necessary, to cool components, extending their
operating life. Under no load and cool ambient temperature no
fan movement may be detected, but this does not indicate fan
failure. Increased load and/or rising ambient temperature should
cause fan activation. No lubrication or maintenance is required.
Simply ensure that there is a free flow of air around the charger
(approximately 4 or more inches around all sides) and that there
is no debris clogging the ventilation perforations in the charger
chassis.
2) Maintenance
A) Filter – The fan (80mm) on the bottom of the charger utilizes a
mesh filter whish is intended to provide some protection against
water from splashing up into the charger. The filter should be
periodically removed and cleaned to prevent unit over heating
Procedure:
1) Disconnect A.C. power and batteries from PT charger.
2) Using a small slotted screw driver, pry off the plastic filter
retainer.
3) Rinse the filter with water or replace.
4) Re-install filter and filter retainer, reconnect A.C. power and
batteries to PT charger.
B) Fan replacement – If the 80mm fan on bottom of charger fails,
it can be replaced in the field. (NOTE: If either of the two smaller
60mm fans fail, the charger should be returned to the factory for
service.)
Procedure:
1) Disconnect A.C. power and all batteries from PT charger.
2) Remove the charger front cover by loosening the four slotted
mounting screws. These screws are captured, do not remove
them.
3) Pull the cover straight off the chassis.
4) Identify the black and red fan power leads. Follow them to an
in-line connector and unplug the connector.
5) Using a small slotted screw driver, remove the filter retainer and
filter.
6) Remove the four Philips flat head screws and remove fan and
finger guard.
7) Remove the four mounting clips from the defective fan and
attach to replacement fan.
8) Mount replacement fan (air flow arrow pointing away from
charger), reconnect fan power leads and re-install fan, finger
guard, filter and filter retainer.
9) Re-install front cover.
Condition
A. Status Indicator shows
charger has shifted into stage
but batteries are not coming
up to full charge.
P.O. Box 1306, Newport Beach, California 92663 • Phone: 714-751-0488 • Fax: 714-957-1621 • E-Mail: techservice@newmarpower.com
Possible Cause
1. High-rate time-out circuit has activated,
but extremely discharged batteries requiring
longer recharge time. See section IV-B for
explanation for time-out circuit.
2. Charger limiting its Output due to overload
3. Charger output is not properly connected to
batteries.
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E) Current Limit Circuit

The Phase Three Charger is self-limiting and protected against
overloads by a fast-acting current limit circuit which automatically
reduces output voltage to protect the charger when a current
demand is encountered which exceeds the charger's power limit
rating. This may be due to extremely discharged batteries which
are beyond the recommended amp-hour rating, or a large D.C.
load being applied while batteries are heavily discharged, for
instance. (See SPECIFICATIONS section for maximum power limited
amps and recommended battery capacity ratings.) If a check of
the output voltage is taken when the charger is under this extreme
current draw, it may measure only a fraction of normal output
voltage. This is a normal function of the current limit circuit. To
check proper charger operation, simply remove the overload and
observe that normal output voltage has automatically resumed.
Important Note: The current limit circuit will not protect the charger
against a dead short across the (+) and (-) output terminals when
the charger is turned on. Charger failure will result.
F) Hight Temperature Output Power Reduction Circuit
In the event of excessive internal temperatures the charger will
automatically reduce its output to approximately 66% of its rated
output. Once the internal circuitry cools the charger, output will
return to a higher output current. If this condition continues, the
charger may need to be relocated to a cooler area or it may be
undersized for the application.

VI) TROUBLESHOOTING

Note 1: The Phase Three charger incorporates a self-contained A.C.
to D.C. conversion module. This module houses several automatic
protection circuits, as well as the A.C. input and D.C. output fuses
to protect internal wiring. Under most circumstances these fuses
will fail only if the charger has an internal fault. They are not
user-replaceable. The following section deals primarily with the
charger's protection features (some requiring manual charger
reset; others auto-resetting). If an apparent charger fault cannot
be corrected using any of the recommendations in this section, the
charger should be returned to the factory or place of purchase for
inspection and repair or replacement.
Note 2: Certain charger or battery problems are self-diagnosing
with the Phase Three charger. For any shutdown condition which
has caused the charger's Status Indicator to signal with one or more
Red L.E.D. "Flash/Beeps" or Yellow Flashes, refer to section IV-C
Status Indicators to diagnose and resolve the problem.
Solution
1. Turn off all D.C. loads and allow charger 24-48 hours
to recharge batteries.
2. Reduce D.C. load.
3. Refer to D.C. wiring section of this manual and verify
compliance with instructions and diagrams
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