Carrier 28QX - Manual (Page 23)

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INITIAL START-UP
Follow this start-up procedure since a proper
start-up is essential to efficient and reliable system
operation. Review Start-Up data in 38HQ heat
pump Installation Instructions and Refrigerant
Charging on pg 27 of this publication.
Plain Water System Start-Up — At this stage of the
installation, all components should be in place, all
piping connections made and all power and low
voltage wires connected. The fused disconnect
should still be in the OFF position. Leave the
disconnect in the OFF position until the procedure
directs otherwise.
SOLAR COLLECTOR PIPING LOOP ^ Begin
filling the storage tank with water. Tap water can
be used as long as dissolved solids do not exceed
800 ppm. Check the storage tank for leaks, espe­
cially the area where supply pipes leave tank. Do
not completely insulate the storage tank until it
has been determined that the tank is leak tight.
Complete the insulation of tank. Add the field-
supplied inhibitor to the storage water. See pg 25.
Before start-up, lubricate collector pump (P2)
bearings on pump package models 34WA257 and
34WA367. Follow oiling instructions on oil tube
and oil warning tag attached to pump. The pump
requires yearly maintenance. Remove shipping
strap from pump on 34WA257 models only.
Fill storage tank until water level is higher than
the highest point in the supply line. Be sure pump
package ball valves and isolation valves are still at
factory set open position (screw heads parallel to
piping). To be sure the pump volute is flooded,
open the uppermost air bleed screw (on pump)
shown below. When water runs thru screw hole, all
the air has been bled out and the screws can be
tightened. Collector pump on 38WA167 does not
trap air and bleeding is not required.
Switch on pump package fused disconnect. If
the sun is out, collector pump will start. If the sun
is not out or water in storage tank is warm, start
the pump by disconnecting one of the collector
sensor leads from the differential control (in pump
package control box). With pump running, check
piping loop for leaks. Determine whether the
system drains properly by shutting off collector
pump, (shut off power or reconnect collector
sensor lead) and listen (at pipe between pump and
collectors) for the water to drain back. Visually
inspect entire system for water traps.
TRI-X COIL LOOP - Bleed air from loop. The air
bleed valve is found at the top of the leaving water
header on the Tri-X coil (or at the highest point in
the loop; see “Tri-X Coil Loop” on pg 13). The
bleed valve consists of a screw in a body with an
exit tube as shown below.
SCREW
EXIT TUBE
By loosening the screw 2 or 3 turns, a path
from the header interior to the exit tube is created.
After loosening the screw, energize the Tri-X pump
by placing a jumper wire between terminals Wi
and A] of Terminal Board 3. Air will make a
hissing sound as it is pushed out of the bleed valve
by the advancing water. When a spout of water
leaves the exit tube, close the screw on the bleed
valve. De-energize the Tri-X pump after allowing it
to run a few minutes with the bleed valve closed.
Repeat the air bleed procedure at a later time
(one-half hour) to be sure all the air is out of the
loop.
Special Water Fill-Up Procedure is required when
the 28QX is mounted more than 6-ft above the
water level in storage tank. (Procedure is same for
plain water or glycol systems.) In these closed loop
circulation systems, the circulator pump does not
have sufficient lift potential to initially fill the piping
loop.
Fig. 28 — Booster Pump Application
Be sure the storage tank is full of water.
Temporarily add a booster pump to the piping
loop. Locate the pump to discharge thru a gate
valve installed in water line between pump package
and 28QX coil. Fig. 28. (If pump is not available, a
garden hose operating at city water pressure can be
used.) Before starting pump, close the ball valve on
the flange of factory circulator pump. Fig. 12 and
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