506162-02
Issue 0847
Page 6 of 14
Heat Pump Application with Electric Heat
Emergency Heat (heating heat pump)
If selector switch on therm ostat is set to the em ergency
heat position, the heat pum p will be locked out of the
heating circuit, and all heating will be electric heat ( if
applicable). A jum per should be placed between W and E
on the therm ostat so that the electric heat control will
transfer to the first stage heat on the therm ostat. This will
allow the indoor blower to cycle on and off with the electric
heat when the fan switch is in the AUTO position.
* Add Jum per on Subbase (Optional)
Start-Up Procedure
1.
Check to ensure:
!
Service valve and gage port caps are installed and
tightened.
!
Voltage supply at unit agrees with nam eplate
rating.
!
Field wiring connections are tight and factory
wiring has not been disturbed and are tight.
!
Indoor fan m otor is on correct speed tap.
2.
Set therm ostat selector switch to OFF and fan control
switch to "Auto" is so equipped.
3.
Close electrical disconnects to energize system .
4.
Set room therm ostat at desired tem perature. Be sure
set point is below indoor am bient tem perature.
5.
Set the system switch of the therm ostat on CO OL (or
HEAT if applicable) and fan switch for continuous
operation (ON) or AUTO, as desired. There will be a
5 m inute short cycle com pressor delay on startup.
Operate unit for 15-20 m inutes, then check the system
refrigerant charge.
6.
Adjust refrigerant charge per "Adjusting Charge"
section.
Adjusting Charge
Factory charge is shown on the rating label located on
the access panel.
All split system heat pum ps are factory charged for
15 feet of connecting line set and m atched indoor fan
coil.
Nam eplate refrigerant charge should initially be
adjusted for line set lengths other than 15 feet. For line
sets shorter than 15 feet in length, rem ove charge. For line
sets longer than 15 feet, add charge. Oil charge is
sufficient for all line lengths.
Before final adjustm ent is m ade to the refrigerant charge,
it is im perative that proper indoor airflow be established.
Airflow will be higher across a dry coil versus a wet coil.
Blower charts are calculated with a
dry or wet coil
basis.
Recom m ended airflow is
350-450 CFM per ton
(12,000
Btuh) through a
w et coil
. Refer to indoor unit instructions
for m ethods of determ ining air flow and blower
perform ance.
Cooling Cycle Charge Adjustm ent
The optim um method for checking the charge is by
w eight. How ever the follow ing methods m ay be used
to confirm the proper charge:
Units with Indoor Pistons
Units installed with indoor pistons require charging with
the superheat m ethod.
The following procedure is valid when indoor airflow is
within ± 20% of its rated CFM.
1.
Operate unit a m inim um of 10 m inutes before
checking charge.
2.
Measure suction pressure by attaching a gage to
suction valve service port. D o not use com pressor
suction port. Determ ine saturation tem p from T/P
chart.
3.
Measure suction tem perature by attaching an
accurate therm istor type or electronic therm om eter
to suction line at service valve.
4.
Calculate superheat (m easured tem p. — saturation
tem p.).
5.
Measure outdoor air dry-bulb tem perature with
therm om eter.
6.
Measure indoor air (entering indoor coil) wet-bulb
tem perature with a sling psychrom eter.
7.
Com pare superheat reading at service valve with the
chart located on control box cover.
8.
If unit has a higher suction line tem perature than
charted tem perature, add refrigerant until charted
tem perature is reached.
9. If unit has a lower suction line tem perature than
charted tem perature, reclaim refrigerant until charted
tem perature is reached.
Refrigeration Charge Adjustm ent
Liquid Line Diam eter
Oz. Per Linear Foot *
3/8"
.6
* Factory charge for series is for 15' (ft.) line sets and matched fan
coil.