4 internal wiring, Section 10.3 – Roberts Gorden Gas-Fired User Manual

Low Intensity Unitary Heater CTH2-100, Low Intensity Unitary Heater CTH2-175, Low Intensity Unitary Heater CTH2-40 CTH2-60, Low Intensity Unitary Heater CTH2-150, Low Intensity Unitary Heater CTH2-125, Low Intensity Unitary Heater CTH2-80