CRD Geothermal System Controls, Electrical & Auxiliary Components 2

Question 1

Which NEC-required electrical protection device is mandatory for geothermal heat pump equipment installed in wet or damp locations?

Accepted Answer

Ground fault circuit interrupter (GFCI)

Answer

The NEC requires GFCI protection for electrical equipment installed in wet or damp locations to protect against ground fault shock hazards.

Question 2

What type of wiring installation is required for geothermal ground loop electrical connections that transition from underground to inside the building?

Accepted Answer

Direct burial-rated cable or appropriate conductors in listed conduit

Answer

Underground electrical connections to flow center pumps must use UF-B (underground feeder) direct burial cable or THWN/THWN-2 conductors in listed conduit rated for wet locations.

Question 3

What electrical component is most effective at protecting geothermal heat pump electronics from utility power surges and voltage transients?

Accepted Answer

Type 2 surge protective device (SPD) at the panel

Answer

A Type 2 surge protective device (SPD) installed at the electrical panel clamps voltage transients before they can damage sensitive heat pump electronics and variable speed drives.

Question 4

What is the primary purpose of a hard start kit (potential relay and start capacitor) used with geothermal heat pump compressors?

Accepted Answer

To reduce locked rotor amperage and provide extra torque during compressor start-up

Answer

A hard start kit reduces inrush (locked rotor) current and provides additional starting torque, which is especially useful on circuits with marginal voltage or when starting against system pressure.

Question 5

What is the standard control voltage used in residential geothermal heat pump low-voltage wiring between the thermostat and air handler?

Accepted Answer

24V AC

Answer

Residential HVAC systems, including geothermal heat pumps, use 24V AC low-voltage control wiring to carry command signals between the thermostat and system components.

(CRD) Certified Residential Geothermal Designer Practice Test

(CRD) Certified Residential Geothermal Designer Practice Test

CRD Geothermal System Controls, Electrical & Auxiliary Components 2