Wiring terminal blocks and terminals - PENN Controls - MR534AFDN - MR534AFDV - Electronic Refrigeration, Defrost, and Multi-Purpose Controller - MR5xx Panel‐Mount Refrigeration and Defrost Controller

MR5 Series Panel Mount Case Controller Installation Guide

Brand
PENN Controls
Product name
MR5xx Panel‐Mount Refrigeration and Defrost Controller
Document type
Installation Guide
Part number
24-07664-03388
Document revision
D
Revision date
2019-08-16
Product status
Discontinued
Language
English

The following figure shows the controller terminal block and terminal designation, internal controller relay actions, and connection purpose.

Figure 1. MR534 terminal block connections
MR534_Rear_Terminal_Display.png

The following table provides information about terminals 1 to 13 on the top terminal block. Sensors SN2 and SN1 are not polarity specific.

Table 1. Top wiring terminal block information
Callout Terminal block label Terminal label Description, function, and requirements Wire size
1 Sensor inputs SN3


Optional. Configure terminal 1 as a case averaging sensor with SN1, or as a defrost averaging sensor with SN2. 0.34 mm2 to 1.5 mm2 (22 AWG to 16 AWG) stranded wires and twisted-leads cable.
2 SN2


Defrost temperature sensor. Connect either sensor lead from SN2. Connect the other lead to a C (common) terminal.
3 SN1


Case temperature sensor. Connect either sensor lead to SN1. Connect the other lead to the C (common) terminal.
4 C Common terminal for the sensors. All low-voltage common terminals are connected.
5 RS 485 + The RS485 Modbus communications terminal block provides a restricted connection to the Modbus connections on an optional precision superheat controller (PSHC). Do not connect any other device to these terminals. 0.14 mm2 to 0.34 mm2 (26 AWG to 22 AWG) stranded wires and twisted-leads cable
6 -
7 REF RS485 Modbus signal reference
8 Analog output AO+ 0 VDC to 10 VDC or 4 mA to 20 mA analog output. Output is 0 VDC to 10 VDC for loads above 1K ohm and 4 mA to 20 mA for loads between 100 ohms to 500 ohms. 0.34 mm2 to 1.5 mm2 (22 AWG to 16 AWG) stranded wires and twisted-leads cable
9 AO- Common terminal for AO-. All common terminals are connected together.
10 LNC Alarm


Alarm relay LNC. Line voltage output terminal. See Table 2 for electrical ratings. 1.5 mm2 to 2.5 mm2

(16 AWG to 14 AWG)

11 LNO Alarm relay LNO. Line voltage output terminal. See Table 2 for electrical ratings.
12 LC Line

COM

Line common. Alarm and evaporator fan and auxiliary relays share the LC terminal (connect to line voltage). See Table 2 and Table 3 for electrical ratings.
13 LNO Fan/Aux


Evaporator fan and auxiliary relay line voltage output terminal. See Table 3 for electrical ratings.

The following table provides information about terminals 14 to 21 on the bottom terminal block. Do not apply any voltage to Binary Input terminals 19, 20, and 21. Connect only user-supplied voltage free contact switches to these terminals.

Table 2. Bottom wiring terminal block information
Callout Terminal block label Terminal label Description, function and requirements Wire size
14 120-240 VAC L1 Two terminals for supply power connection to the MR534 Controller. See the Supply Power row in Table 1. 0.75 mm2 to 2.5 mm2

(18 AWG to 14 AWG)

15 L2
16 LC Line

COM

Line Common. Defrost and compressor relays share the LC terminal (connect to line voltage). See Table 1 and Table 4 for electrical ratings. 1.5 mm2 to 2.5 mm2

(16 AWG to 14 AWG)

17 LNO Def


Defrost heater relay line voltage output terminal. See Table 4 for electrical ratings.
18 LNO Comp


Compressor relay line voltage output terminal. See Table 1 for electrical ratings.
19 Binary input C Common terminal for binary inputs 0.34 mm2 to 1.5 mm2

(22 AWG to 16 AWG)

stranded wires and twisted-leads cable.
20 BI1 Open or closed state detection. Connect to a user-supplied voltage free contact switch only.
21 BI2