# Switchroom heater auxiliary feeder

Canonical URL: https://eloragrid.ai/symbols/switchroom-heater-auxiliary-feeder
Publisher: Elora Grid
Updated: 2026-11-03
Lookup label: SHAF
Drawing use: Schematic
Reference families: Manufacturer

Representation: Functional block
Installation focus: switchrooms
Input: Heater supply branch
Output: Conditioning heater input

Shows the assigned supply circuit for room or enclosure conditioning heaters.

## In plain English

### What this block does

Shows the assigned supply circuit for room or enclosure conditioning heaters.

### A simple example

In a switchroom, the lighting, service sockets, charger input and room cooling may be fed from different auxiliary branches. A source change must preserve the identities of loads that require continuity. For this reference, the drawing identifies “Heater supply branch” at the input and “Conditioning heater input” at the output. Heater availability does not establish humidity control.

### What the drawings help you do

Start at the named input: Heater supply branch. Identify its source device or document and the state represented on the drawing. Follow the named output: Conditioning heater input. Cross-reference its destination and separate the command from confirmation that the equipment responded.

### Terms

- Input: Heater supply branch
- Output: Conditioning heater input
- Application reference: An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections.

Concept diagram: Heater supply branch → SHAF → Conditioning heater input
A reading guide. The entry's original illustration and input/output facts describe this application.

- [SEL-RPM redundant power module](https://selinc.com/products/RPM/)


## What it represents

Shows the assigned supply circuit for room or enclosure conditioning heaters. An auxiliary AC distribution diagram identifies the supplies serving room services and control-support equipment. Essential, backed-up and ordinary circuits can have different source paths and operating priorities.
In a switchroom, the lighting, service sockets, charger input and room cooling may be fed from different auxiliary branches. A source change must preserve the identities of loads that require continuity. For this reference, the drawing identifies “Heater supply branch” at the input and “Conditioning heater input” at the output. Heater availability does not establish humidity control.
Label source, branch protection and load purpose. The arrangement does not establish conductor sizes, protection settings or installation compliance; it links the operating role to the selected equipment schedule. The functional block is an independent explanation of this named application. Equipment-specific ratings, terminal connections and operating conditions must be established in the project documentation.

## How to read it

- Start at the named input: Heater supply branch. Identify its source device or document and the state represented on the drawing.
- Follow the named output: Conditioning heater input. Cross-reference its destination and separate the command from confirmation that the equipment responded.
- Heater availability does not establish humidity control.
- Label source, branch protection and load purpose. The arrangement does not establish conductor sizes, protection settings or installation compliance; it links the operating role to the selected equipment schedule.

## Information to show or reference

- Label the source and connection reference for heater supply branch.
- Identify the destination and defined state of conditioning heater input.
- Record the equipment or control-document revision supporting this functional block.
- Check this application limit in the project design: Heater availability does not establish humidity control.

## Important distinction

Heater availability does not establish humidity control. This reference describes the named application; it does not establish a new IEC graphical symbol, an ANSI device-function number or an exact manufacturer connection diagram.

## Facts

- Representation: Functional block
- Installation focus: Switchrooms
- Input / boundary: Heater supply branch
- Output / connection: Conditioning heater input
- Lookup label: SHAF is a library lookup label, not a standard device designation.

## Public references

- [SEL-RPM redundant power module](https://selinc.com/products/RPM/) — SEL. Public technical context for switchroom auxiliary ac distribution. Independent AC and DC sources for station auxiliary power. The application text and educational graphic are independently authored; the publisher does not certify this representation.

## Graphic scope

Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.