Series
Fan-Powered
CONFIDENTIAL DOCUMENT. FOR INTERAL USE ONLY. 41VAV-SLM005-EN
Feature
Evaluation
SCR Electric Heat Control
Trane does not offer an option for SCR Electric Heat Control. Our competitors use
SCR electric heat control, which is very expensive. We can achieve a modulating kW
operation using our DDC controls. Using pulse-width modulation, our DDC UCM
calculates how far from setpoint the temperature is and what percentage of the
electric heat it need to bring to satisfy the zone.
Suggested Spec
Pulse-Width Modulated (PWM)—At heating setpoint, energize first stage of heat. The
second stage of heating shall be energized based on time and temperature deviation
from setpoint. Duty-cycle these stages on a three-minute window. Stage 1 shall
modulate from 0–50 percent deviation and be on continuously above 50%. Stage 2
shall modulate from 50–100 percent deviation.
Lower Damper Leakage
Our damper leakage rate is 1% @ 4 in. wg and Nailor’s leakage rate is 2% @ 3 in. wg.
Nailor’s higher rate is the result of an opposed blade damper design, which generally
has a higher leakage rate.
