Apollo IMY instruction manual Wiring Connections, Power Wiring

WIRING CONNECTIONS

After the unit has been mechanically mounted, it is ready to be wired. All conductors should meet voltage and current ratings for each terminal. Also cabling should conform to approriate standards of good installation, local codes, and regulations. It is recommended that power supplied to the unit be protected by a fuse or circuit breaker. All wiring connections are made on removable plug-in terminal blocks. There is a separate terminal block for the bottom board (TBA) and optional top board (TBB). When wiring the unit, remove the terminal block and use the numbers on the label to identify the position number with the proper function. Strip the wire, leaving approx. 1/4" bare wire exposed (stranded wires should be tinned with solder). Insert the wire into the terminal and tighten down the screw until the wire is clamped tightly. Each terminal can accept up to one 14-gauge, two 18-gauge or four 20-gauge wire(s). After the terminal block is wired, install it into proper location on the PC board. Wire each terminal block in this manner.

POWER WIRING

Primary AC power is connected to terminal 1 and 2 (marked VAC 50/60 Hz, located on the left hand side of the bottom terminal block). To reduce the chance of noise spikes entering the AC line and affecting the indicator, the AC power should be relatively “clean” and within the specified ￿10% variation limit. Drawing power from heavily loaded circuits or circuits which also power loads that cycle on and off, (contactors, relays, motors, machinery, etc.) should be avoided.

SIGNAL WIRING (THERMISTOR)

Meter signal input common is not isolated from PGM. DIS., E1-CON, E2-CON; maximum allowable 50 V can be present in the circuit that is being measured.

Thermistors provide a higher degree of accuracy, stability, and resolution over other temperature sensing elements, such as platinum RTDs or thermocouples.

The IMY supports two popular types of thermistors; the 400 Series (YSI 44000) 2,252￿ thermistor, and the 700 Series “Thermolinear￿” thermistor. Selection of the two types is done in Programming Module #1.

The 400 Series thermistor is a 2-wire sensor. One lead connects to TBA #6 (T1) and the other lead connects to TBA #7 (comm).

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The 700 Series Thermolinear￿ thermistor is a 3-wire sensor. One lead connects to TBA #6 (T1) and the common lead connects to TBA #7 (comm). The third wire is an additional thermistor lead and connects to TBA #5 (T2).

Always refer to the sensor manufacturer’s instructions for probe wiring connections, if available.

A.C. Powered Basic Connection

USER INPUT WIRING

User inputs (PGM.DIS., E1-CON, and optional E2-CON) are digital inputs that are active when connected to TBA #5 Common. Any form of mechanical switch, sinking collector logic with less than 0.7 V saturation may be used. The use of shielded cable is recommended. Follow the EMC Installation Guidelines for shield connection.

OUTPUT WIRING

Relay Connections

To prolong contact life and suppress electrical noise interference due to the switching of inductive loads, it is good installation practice to install a snubber across the contactor. Follow the manufacturer’s instructions for installation.

Note: Snubber leakage current can cause some electro-mechanical devices to be held ON.