Checking universal inputs for 0v, Checking universal input source voltage – Innotech Maxim User Manual

Page 47

Page 47

MAXIM Installation Instructions

Chapter 5 – Commissioning

CHECKING UNIVERSAL

INPUT SOURCE VOLTAGE

Connected to equipment

or device

Disconnected from

MAXIM controller

EARTH

5-2.2.2 Checking Universal Inputs

Before any Universal Inputs are connected to a MAXIM Series controller, you MUST follow the steps

listed below to verify that 0VAC is measured across these inputs. Please note that the voltage will be

measured directly at the Universal Input wiring, and NOT at the controller, as illustrated in Figure 5-2

below. These steps do not apply if a DC source is connected to the Universal Inputs. In this case the

expected voltage to be measured would be that of the source voltage.

Please note that these instructions are also applicable in situations where a Universal Input / Output

on a MAXIM Series controller is configured as a Universal Input. The Universal Input / Output can be

commissioned according to whether it is configured as a Universal Input or a Universal Output.

1. Verify that ALL Universal Inputs are labelled and disconnected from the controller.
2. Verify that the power to the controller is turned OFF.
3. Verify that the power to the equipment to which the Universal Inputs are connected is turned

OFF.

4. Set the DMM voltage range to measure at least 25VAC; the AUTO setting will suit most

measurements.

5. Connect the red (+) lead of the DMM to the Universal Input wire labelled (+), and the black (–)

lead of the DMM to EARTH, as illustrated in Figure 5-2 below.

6. Observe and verify that the DMM measures 0VAC across the Universal Input wiring. If the

reading is not 0VAC, this could possibly mean that the wiring is incorrect, or the Universal Input

source may not be turned OFF.

Once you have performed these steps and verified 0V is measured across each Universal Input

wiring, reconnect the wiring one by one to the corresponding Universal Input terminal on the MAXIM

controller. It is important to observe the polarity when reconnecting the wiring to the controller.

Figure 5-2: Checking Universal Inputs for 0V