Carrier 38HQ User Manual

Carrier	38HQ
H Weathermastcr ID	Cooling: 29,000 and 34,500 Btuh
	Heating: 42,000 and 48,000 Btuh
^ Dual-Compressor
Heat Pump System

&,^A unique breakthru toward super-efficiency in heating and cooling

$) Carrier Corporation 1373	Form 38BQ-3?

It’s like having two heat pumps in one!

Carrier engineers have developed the most skillfully designed and	balance point), the second compressor automatically energizes to	t
unique heat pump systems since the first heat pump was built by	boost system capacity to provide more heat with high efficiency
Carrier back in 1932 The 38HQ is far more than a conventional	Once the system reaches its second thermal balance point, aux­
heat pump it’s more like having two extra-efficient heat pumps	iliary electric heaters can provide enough heat for indoor comfort
in one And there’s no other like it	even on the most frigid winter nights
The 38HQ joins the quality-proven family of Weathermaster III	When cooling, the 38HQ system reverses the heating cycle by
heat pump systems The added feature of a second compressor	removing heat from indoors and rejecting it outdoors The cooling
provides extra operating efficiency for heating at lower outdoor	cycle uses one of the compressors, the one sized to meet the total
temperatures	cooling load

The energy-saving principle of reverse cycle heating and cooling

Like other Carrier heat pumps, the 38HQ is an electrically operated system that provides comfortable temperatures for your home all year long When heating, the system absorbs heat from cold outside air (even sub-zero outdoor air contains usable heat) and brings it inside to heat your home

Unlike other residential heat pumps, the 38HQ has a twocompressor capability that makes it ideal for areas prone to extreme, prolonged winter cold By establishing a second thermal balance point for the system (see right), more heat at lower energy cost is made available than would be in a conventional onecompressor system Since over half of North America experiences 7000 or more heating degree days per year, the dual-compressor system makes good heating sense. The extra capacity of the 38HQ provides higher heating output at lower annual energy cost Even in more temperate regions, the dual-compressor system offers dependable, efficient operation Here’s how it works

If the outdoor temperature drops to a level at which the first compressor can no longer deliver enough heat (the first thermal

Any single-compressor heat pump teaches a theimal balance point where insufficient heat can be extracted from outdoors (A) The piesence of the second compressoi in the dual compressor 38HQ system extends highefficiency heat pump heating operation to a second, lower thermal balance point (B) to piovide significant dollar savings

Three reasons to buy the Weathermaster III

Dual	Compressor	capacities of 29,000 and 34,500 Btuh cooling, 42,000 and 48,000 Btuh heating
		The 38HQ dual-compressor heat pump system is available in two sizes with
Heat Pump		The system consists of three separate components — indoor fan-coil, outdoor
		coil, and compressor section — to afford maximum flexibility, accessibility
		and easy maintenance

1. Compressor Section

Two compressors fit compactly into one con­ venient enclosure that can be installed in your garage, utility room, breezeway or basement This allows the compressors to be sheltered, away from bad weather, yet remain easily accessible for servicing This easy accessibility can translate directly into dollars saved on labor costs

Compressor muffler and special acoustical treatment reduce operating sound All connec­ tions are on top of the enclosure to speed installa­ tion. Top cover and front panel are removable for ready access to compressors, reversing value, control system, and related components. The second compressor is preset by the installer to activate automatically when needed, assuring dependable operation at lowest cost for your particular area

2. Outdoor Section

This distinctively styled unit is Cairier’s popular Round One Only the king-size circular coil, outdoor fan and motor, and control box are con tained in this enclosure Because of its light weight, this section can easily be mounted on a wall instead of on the ground, protecting it from pets and growing shrubbery Wall-mounting is also beneficial in heavy snowfall regions

3. Indoor Section

No special indoor coil is needed for the 38HQ dual-compressor system Select the indoor sec tion from a variety of approved Can ier heat pump system coils and fan sections

A combination of the 28HQ horizontal or 28VQ vertical coil plus the 40FS modular fan section provides a simply installed, easy to maintain indoor section for upflow, downflow or horizontal applications

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VL

CLIC and OP-CLIC: Finding the best system for your needs

Carrier now offers two computer services to your dealer to provide posi­ tive assurance that you’re getting the right equipment, sized to meet your needs at the best possible price.

Using the telephone right in your home, your dealer can use CLIC (Carrier Load Information Center) to determine the heating and cooling loads for your home, and then, by feeding the proper information into the computer, he can use OP-CLIC (Carrier Annual Operating Cost Analysis Computer Program) to determine optimum balance points and annual operating costs for your system.

Quality features make the dual-compressor heat pump an unbeatable value

Two rugged Carrier compressors, built to withstand the rigorous requirements of year round heat pump duty, provide reliable system operation. Compressors have factory-installed overcurrent and internal overtemperature protection Suction line accumulator protects compressors from refrigerant floodback. Crankcase heaters prevent dilution of oil by refrigerant when unit is off. Each compres­ sor has internal pressure relief protection. Start capacitors and relays are standard.

Wrap-around coil in the outdoor section is designed for maximum efficiency. All-aluminum coil provides superior heat transfer.

High volume, low speed outdoor fan quietly discharges air and sound up and away from surrounding homes and neighbors. The quiet fan permits installation in a variety of locations and delivers excellent performance without disturbing the neighborhood.

AccuRater™ combination metering device and check valve provides efficient refrigerant flow for the most economical system operation.

Chronotemp defrost device removes frost from coil when required Saves on operating costs because it’s keyed to both time and temperature.

Liquid line low-pressure switch, combined with com­ pressor internal overloads, provides loss of charge protection

Outdoor thermostat controls operation of second com­ pressor in response to outdoor temperature.

Signal-Loc’^“ system malfunction warning indicator and lockout — This solid state logic circuit indicates when a system malfunction occurs and locks out compressor(s) for protection. The emergency heat light on the wall thermo­ stat comes on when low-pressure switch functions or when compressor(s) fails to run on thermostat demand. The light goes out when thermostat is satisfied or when compressor starting is attempted by manually setting the thermostat off, then on. If light remains on after manually resetting thermostat, service is probably required.

Indoor fan speed controller increases indoor fan speed during periods when second compressor is on, thereby increasing system efficiency.

Low voltage (24 v) terminal board is provided for easy system installation.