Aaon ASM01691 VCC-X EM1 VCCX Expansion Module Control Board

The Aaon ASM01691 is an OEM VCC-X EM1 Expansion Module (also known as the VCCX-EM1 board) manufactured by Aaon Controls, formerly Wattmaster Controls. This expansion board connects to compatible VCCX-series controllers — including the VCCX2, VCCX-IP, and VCCX-454 — via an E-BUS cable to provide additional inputs and outputs beyond what the base controller offers.

Inputs & Outputs:

• 5 Analog Inputs
• 5 Analog Outputs (0–10 VDC or 2–10 VDC configurable)
• 3 Binary Inputs — including Return/Exhaust Proof of Flow, Direct Fire Status Signal, and Direct Fire Alarm Signal
• 5 Configurable Relay Outputs (24 VAC wet contacts, 1A maximum load)

Key Features:

• Adds Title 24 (FDD) Economizer Feedback capability
• Supports Modulating Chilled Water Valve control
• Provides Return Air Bypass Damper and Return Air Damper analog outputs
• Supports Motorized Exhaust Damper control
• Compatible with the E-BUS 12 Relay Expansion Module for further I/O expansion
• Housed in a plastic enclosure with three mounting holes for panel or surface mounting (includes #8 x 1" sheet metal screws)

Electrical & Environmental Specifications:

• Operating Power: 18–30 VAC
• Power Consumption: 5 VA Maximum
• Operating Temperature: -22°F to 158°F
• Operating Humidity: 0–95% RH, Non-Condensing

Cross-Reference Part Numbers: OE336-23-VCCXEM1 (Orion/Wattmaster), V53990 (legacy AAON). This is a genuine OEM replacement part designed for AAON commercial HVAC rooftop units requiring expanded controller I/O for advanced applications including chilled water, economizer feedback, and return air bypass.